Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Materials (Basel) ; 17(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38893969

RESUMO

The microstructure and texture evolution of Cu-Ni-P alloy after cold rolling and annealing at 500 °C was studied by electron backscattering diffraction (EBSD). The equiaxed grain is elongated and the dislocation density increases gradually after cold rolling. The grain boundaries become blurred and the structure becomes banded when the reduction in cold rolling reaches 95%. A typical rolling texture is formed with the increase in deformation amount in cold rolling. The deformation structure gradually disappeared and recrystallized new grains were formed after annealing at 500 °C. The recrystallization nucleation mechanism of Cu-Ni-P alloy at 60% reduction is mainly a bow nucleation mechanism. A shear band begins to form after annealing at 80% reduction. The shear band becomes the preferred nucleation location with the increase in reduction. Most adjacent recrystallized grains growing in the shear band have a twin relationship.

2.
Eur Radiol ; 33(12): 8809-8820, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37439936

RESUMO

OBJECTIVES: To develop and validate a radiomics-based model (ADGGIP) for predicting adult-type diffuse gliomas (ADG) grade by combining multiple diffusion modalities and clinical and imaging morphologic features. METHODS: In this prospective study, we recruited 103 participants diagnosed with ADG and collected their preoperative conventional MRI and multiple diffusion imaging (diffusion tensor imaging, diffusion kurtosis imaging, neurite orientation dispersion and density imaging, and mean apparent propagator diffusion-MRI) data in our hospital, as well as clinical information. Radiomic features of the diffusion images and clinical information and morphological data from the radiological reports were extracted, and multiple pipelines were used to construct the optimal model. Model validation was performed through a time-independent validation cohort. ROC curves were used to evaluate model performance. The clinical benefit was determined by decision curve analysis. RESULTS: From June 2018 to May 2021, 72 participants were recruited for the training cohort. Between June 2021 and February 2022, 31 participants were enrolled in the prospective validation cohort. In the training cohort (AUC 0.958), internal validation cohort (0.942), and prospective validation cohort (0.880), ADGGIP had good accuracy in predicting ADG grade. ADGGIP was also significantly better than the single-modality prediction model (AUC 0.860) and clinical imaging morphology model (0.841) (all p < .01) in the prospective validation cohort. When the threshold probability was greater than 5%, ADGGIP provided the greatest net benefit. CONCLUSION: ADGGIP, which is based on advanced diffusion modalities, can predict the grade of ADG with high accuracy and robustness and can help improve clinical decision-making. CLINICAL RELEVANCE STATEMENT: Integrated multi-modal predictive modeling is beneficial for early detection and treatment planning of adult-type diffuse gliomas, as well as for investigating the genuine clinical significance of biomarkers. KEY POINTS: • Integrated model exhibits the highest performance and stability. • When the threshold is greater than 5%, the integrated model has the greatest net benefit. • The advanced diffusion models do not demonstrate better performance than the simple technology.


Assuntos
Neoplasias Encefálicas , Glioma , Adulto , Humanos , Imagem de Tensor de Difusão/métodos , Estudos Prospectivos , Neoplasias Encefálicas/diagnóstico por imagem , Gradação de Tumores , Estudos Retrospectivos , Glioma/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/métodos
3.
BMC Plant Biol ; 23(1): 251, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37173622

RESUMO

Phytoplasmas are obligate cell wall-less prokaryotic bacteria that primarily multiply in plant phloem tissue. Jujube witches' broom (JWB) associated with phytoplasma is a destructive disease of jujube (Ziziphus jujuba Mill.). Here we report the complete 'Candidatus Phytoplasma ziziphi' chromosome of strain Hebei-2018, which is a circular genome of 764,108-base pairs with 735 predicted CDS. Notably, extra 19,825 bp (from 621,995 to 641,819 bp) compared to the previously reported one complements the genes involved in glycolysis, such as pdhA, pdhB, pdhC, pdhD, ackA, pduL and LDH. The synonymous codon usage bias (CUB) patterns by using comparative genomics analysis among the 9 phytoplasmas were similar for most codons. The ENc-GC3s analysis among the 9 phytoplasmas showed a greater effect under the selection on the CUBs of phytoplasmas genes than mutation and other factors. The genome exhibited a strongly reduced ability in metabolic synthesis, while the genes encoding transporter systems were well developed. The genes involved in sec-dependent protein translocation system were also identified.The expressions of nine FtsHs encoding membrane associated ATP-dependent Zn proteases and Mn-SodA with redox capacity in the Ca. P. ziziphi was positively correlated with the phytoplasma concentration. Taken together, the genome will not only expand the number of phytoplasma species and provide some new information about Ca. P. ziziphi, but also contribute to exploring its pathogenic mechanism.


Assuntos
Phytoplasma , Ziziphus , Phytoplasma/genética , Plantas/genética , Códon , Ziziphus/genética , Ziziphus/metabolismo , Mutação , Doenças das Plantas/microbiologia
4.
BMC Plant Biol ; 21(1): 527, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34763664

RESUMO

BACKGROUND: SEPALLATA3 (SEP3), which is conserved across various plant species, plays essential and various roles in flower and fruit development. However, the regulatory network of the role of SEP3 in flowering time at the molecular level remained unclear. RESULTS: Here, we investigated that SEP3 in Ziziphus jujuba Mill. (ZjSEP3) was expressed in four floral organs and exhibited strong transcriptional activation activity. ZjSEP3 transgenic Arabidopsis showed an early-flowering phenotype and altered the expression of some genes related to flowering. Among them, the expression of LATE ELONGATED HYPOCOTYL (AtLHY), the key gene of circadian rhythms, was significantly suppressed. Yeast one-hybrid (Y1H) and electrophoretic mobility shift assays (EMSAs) further verified that ZjSEP3 inhibited the transcription of AtLHY by binding to the CArG-boxes in its promoter. Moreover, ZjSEP3 also could bind to the ZjLHY promoter and the conserved binding regions of ZjSEP3 were found in the LHY promoter of various plant species. The ectopic regulatory pathway of ZjSEP3-AtLHY was further supported by the ability of 35S::AtLHY to rescue the early-flowering phenotype in ZjSEP3 transgenic plants. In ZjSEP3 transgenic plants, total chlorophyll content and the expression of genes involved in chlorophyll synthesis increased during vegetative stages, which should contribute to its early flowering and relate to the regulatory of AtLHY. CONCLUSION: Overall, ZjSEP3-AtLHY pathway represents a novel regulatory mechanism that is involved in the regulation of flowering time.


Assuntos
Flores/genética , Regulação da Expressão Gênica de Plantas , Regiões Promotoras Genéticas , Ziziphus/genética , Motivos de Aminoácidos , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Sequência Conservada , Flores/crescimento & desenvolvimento , Genes de Plantas , Filogenia , Plantas Geneticamente Modificadas/genética , Transcrição Gênica , Transcriptoma
5.
BMC Genomics ; 21(1): 483, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32664853

RESUMO

BACKGROUND: Among several TF families unique to eukaryotes, the basic leucine zipper (bZIP) family is one of the most important. Chinese jujube (Ziziphus jujuba Mill.) is a popular fruit tree species in Asia, and its fruits are rich in sugar, vitamin C and so on. Analysis of the bZIP gene family of jujube has not yet been reported. In this study, ZjbZIPs were identified firstly, their expression patterns were further studied in different tissues and in response to various abiotic and phytoplasma stresses, and their protein-protein interactions were also analyzed. RESULTS: At the whole genome level, 45 ZjbZIPs were identified and classified into 14 classes. The members of each class of bZIP subfamily contain a specific conserved domain in addition to the core bZIP conserved domain, which may be related to its biological function. Relative Synonymous Codon Usage (RSCU) analysis displayed low values of NTA and NCG codons in ZjbZIPs, which would be beneficial to increase the protein production and also indicated that ZjbZIPs were at a relative high methylation level. The paralogous and orthologous events occurred during the evolutionary process of ZjbZIPs. Thirty-four ZjbZIPs were mapped to but not evenly distributed among 10 pseudo- chromosomes. 30 of ZjbZIP genes showed diverse tissue-specific expression in jujube and wild jujube trees, indicating that these genes may have multiple functions. Some ZjbZIP genes were specifically analyzed and found to play important roles in the early stage of fruit development. Moreover, some ZjbZIPs that respond to phytoplasma invasion and abiotic stress environmental conditions, such as salt and low temperature, were found. Based on homology comparisons, prediction analysis and yeast two-hybrid, a protein interaction network including 42 ZjbZIPs was constructed. CONCLUSIONS: The bioinformatics analyses of 45 ZjbZIPs were implemented systematically, and their expression profiles in jujube and wild jujube showed that many genes might play crucial roles during fruit ripening and in the response to phytoplasma and abiotic stresses. The protein interaction networks among ZjbZIPs could provide useful information for further functional studies.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/genética , Ziziphus/genética , Fatores de Transcrição de Zíper de Leucina Básica/isolamento & purificação , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Mapeamento Cromossômico , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla/métodos , Filogenia , Phytoplasma/metabolismo , Estresse Fisiológico/genética , Ziziphus/classificação
6.
Tree Physiol ; 40(10): 1437-1449, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32483619

RESUMO

Reactive oxygen species (ROS) in plants increase dramatically under pathogen attack, and the antioxidant defense system is then triggered to protect the plant against the ROS. Jujube witches' broom disease (JWB), caused by phytoplasma, is a destructive disease of Chinese jujube. The results of fluorescence-based measurement revealed that ROS were overproduced within jujube leaves after phytoplasma invasion. Furthermore, analysis based on mRNA and metabolite levels revealed that ascorbic acid (AsA) metabolism was strengthened under phytoplasma stress. The high expression of genes involved in the AsA/glutathione (GSH) cycle and thioredoxin (Trx) synthesis in diseased leaves indicated that GSH and Trx actively respond to phytoplasma infection. Moreover, higher activities of enzymatic antioxidants and the upregulated expression of related genes were confirmed in diseased tissues. Both nonenzymatic and enzymatic antioxidants in the host jujube were strongly stimulated to cope with ROS caused by phytoplasma stress. Compared with that in the susceptible variety, the activities of glutathione S-transferase and peroxidase in the resistant variety at the earlier infection stage were higher, indicating that enzymes might be involved in the resistance to phytoplasma. These results highlight the roles of the antioxidant defense system of the host plant in the tolerance to phytoplasma invasion.


Assuntos
Phytoplasma , Ziziphus , Antioxidantes , China , Doenças das Plantas
7.
BMC Genomics ; 21(1): 142, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041543

RESUMO

BACKGROUND: Mitogen-activated protein kinase (MAPK) cascades play vital roles in signal transduction in response to a wide range of biotic and abiotic stresses. In a previous study, we identified ten ZjMAPKs and five ZjMAPKKs in the Chinese jujube genome. We found that some members of ZjMAPKs and ZjMAPKKs may play key roles in the plant's response to phytoplasma infection. However, how these ZjMAPKKs are modulated by ZjMAPKKKs during the response process has not been elucidated. Little information is available regarding MAPKKKs in Chinese jujube. RESULTS: A total of 56 ZjMAPKKKs were identified in the jujube genome. All of these kinases contain the key S-TKc (serine/threonine protein kinase) domain, which is distributed among all 12 chromosomes. Phylogenetic analyses show that these ZjMAPKKKs can be classified into two subfamilies. Specifically, 41 ZjMAPKKKs belong to the Raf subfamily, and 15 belong to the MEKK subfamily. In addition, the ZjMAPKKKs in each subfamily share the same conserved motifs and gene structures. Only one pair of ZjMAPKKKs (15/16, on chromosome 5) was found to be tandemly duplicated. Using qPCR, the expression profiles of these MAPKKKs were investigated in response to infection with phytoplasma. In the three main infected tissues (witches' broom leaves, phyllody leaves, and apparently normal leaves), ZjMAPKKK26 and - 45 were significantly upregulated, and ZjMAPKKK3, - 43 and - 50 were significantly downregulated. ZjMAPKKK4, - 10, - 25 and - 44 were significantly and highly induced in sterile cultivated tissues infected by phytoplasma, while ZjMAPKKK6, - 7, - 17, - 18, - 30, - 34, - 35, - 37, - 40, - 41, - 43, - 46, - 52 and - 53 were significantly downregulated. CONCLUSIONS: For the first time, we present an identification and classification analysis of ZjMAPKKKs. Some ZjMAPKKK genes may play key roles in the response to phytoplasma infection. This study provides an initial understanding of the mechanisms through which ZjMAPKKKs are involved in the response of Chinese jujube to phytoplasma infection.


Assuntos
MAP Quinase Quinase Quinases/genética , Phytoplasma , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Ziziphus , Regulação para Baixo , Regulação da Expressão Gênica de Plantas , Filogenia , Ziziphus/genética , Ziziphus/imunologia , Ziziphus/microbiologia
8.
Zoonoses Public Health ; 66(7): 879-885, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31334609

RESUMO

Understanding the socioeconomic burden of severe fever with thrombocytopenia syndrome (SFTS) is important for making decisions on health resources allocation. This study aimed to assess the economic burden of patients with this syndrome in endemic areas of the Anhui Province in 2018. A total of 114 patients were recruited, and the median age was 63.5 years, 62 (54.4%) were female, 97 (85.1%) were farmers, 108 (94.7%) were survival patients, and 71 (62.3%) had a family monthly income less than $453.3. The median times of hospital visits and hospitalizations of patients were three times, and the median lost work days of these patients, caregivers and visitors were 14.5 days, 14.5 days and 7.5 days, respectively. The median direct costs of the patient were $3,761.6, and the median indirect costs were $508.3. Taking direct and indirect costs into consideration, the median total economic costs of patients were $4,323.9, and the total annual cost of 2018 was $1,396,913.6. Although 113 (99.1%) patients had medical insurance, only 25.8% of costs were covered by reimbursement, and the total cost paid for by the patients and their families was $1,041,073.6 in 2018. Our findings revealed that the patients and their families had a significant economic burden, and preventive measures should be strengthened in endemic areas. The findings also provided baseline data for assessing the cost-effectiveness of the vaccines or anti-viral drugs in the near future in China.


Assuntos
Infecções por Bunyaviridae/economia , Infecções por Bunyaviridae/virologia , Phlebovirus , Animais , Infecções por Bunyaviridae/epidemiologia , China/epidemiologia , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores Socioeconômicos , Inquéritos e Questionários
9.
BMC Genomics ; 20(1): 568, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291886

RESUMO

BACKGROUND: The bHLH (basic helix-loop-helix) transcription factor is one of the largest families of transcription factors in plants, containing a large number of members with diverse functions. Chinese jujube (Ziziphus jujuba Mill.) is the species with the highest economic value in the family Rhamnaceae. However, the characteristics of the bHLH family in the jujube genome are still unclear. Hence, ZjbHLHs were first searched at a genome-wide level, their expression levels under various conditions were investigated systematically, and their protein-protein interaction networks were predicted. RESULTS: We identified 92 ZjbHLHs in the jujube genome, and these genes were classified into 16 classes according to bHLH domains. Ten ZjbHLHs with atypical bHLH domains were found. Seventy ZjbHLHs were mapped to but not evenly distributed on 12 pseudo- chromosomes. The domain sequences among ZjbHLHs were highly conserved, and their conserved residues were also identified. The tissue-specific expression of 37 ZjbHLH genes in jujube and wild jujube showed diverse patterns, revealing that these genes likely perform multiple functions. Many ZjbHLH genes were screened and found to be involved in flower and fruit development, especially in earlier developmental stages. A few genes responsive to phytoplasma invasion were also verified. Based on protein-protein interaction prediction and homology comparison, protein-protein interaction networks composed of 92 ZjbHLHs were also established. CONCLUSIONS: This study provides a comprehensive bioinformatics analysis of 92 identified ZjbHLH genes. We explored their expression patterns in various tissues, the flowering process, and fruit ripening and under phytoplasma stress. The protein-protein interaction networks of ZjbHLHs provide valuable clues toward further studies of their biological functions.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Genômica , Proteínas de Plantas/genética , Ziziphus/genética , Cromossomos de Plantas/genética , Sequência Conservada , Flores/crescimento & desenvolvimento , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Motivos de Nucleotídeos/genética , Filogenia , Phytoplasma/fisiologia , Ziziphus/crescimento & desenvolvimento , Ziziphus/microbiologia
10.
Am J Trop Med Hyg ; 100(3): 652-658, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30675836

RESUMO

This study aimed to assess baseline knowledge, attitudes, and practices about severe fever with thrombocytopenia syndrome (SFTS) and identify the target population for health education programs in endemic areas of Anhui, China. This cross-sectional study was conducted from May to June 2017. Of 752 participants, 383 (50.9%) were from Nanqiao District, 397 (52.8%) were female, and 430 (57.2%) were farmers; 37.4% had heard about SFTS, but knowledge of symptoms and signs including fever (34.2%), leukopenia (8.0%), and thrombocytopenia (10.1%) was low. Only 12.1% knew that SFTS virus is transmitted by ticks, 9.4% realized that the blood and body fluid of SFTS are infectious, and only 38.2% thought that the tick should be paralyzed using medical alcohol or iodine. Meanwhile, 61.3% wore long-sleeve clothes, whereas 20.2% used repellents. Median scores for knowledge, attitudes, and practices, and the total score were 4.0, 6.0, 5.0, and 16.0, respectively. Knowledge was influenced by region (OR = 0.632, 95% CI: 0.399-0.999), education (OR = 0.516, 95% CI: 0.434-0.612), gender (OR = 1.865, 95% CI: 1.165-2.987), and age (OR = 3.406, 95% CI: 2.345-4.947). Education was a predictor of lack of appreciation of infection risk (OR = 0.519, 95% CI: 0.449-0.599) and practice (OR = 0.481, 95% CI: 0.396-0.584). Our findings indicate that SFTS-related health education programs are required for females; participants from Qianshan Prefecture; those with an occupation of farmer, retiree, houseworker, or unemployed; elderly participants; and those with low education. Large-scale sustainable health education programs focusing on the target populations are urgently needed in endemic areas.


Assuntos
Infecções por Bunyaviridae/epidemiologia , Infecções por Bunyaviridae/virologia , Conhecimentos, Atitudes e Prática em Saúde , Phlebovirus , Adulto , Idoso , Infecções por Bunyaviridae/prevenção & controle , China/epidemiologia , Estudos Transversais , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
Phytopathology ; 108(9): 1067-1077, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29648946

RESUMO

Phytoplasmas parasitize plant phloem tissue and cause many economically important plant diseases. Jujube witches'-broom disease is a destructive phytoplasma disease of Chinese jujube (Ziziphus jujuba). To elucidate the influence of phytoplasma on host photosynthetic, carbohydrate and energy metabolisms, four types of jujube tissues showing disease symptoms with different severity were investigated at the structural, physiological, and molecular levels. Quantitative real-time PCR and high-performance liquid chromatography results showed that the down-regulation of genes related to photosynthesis and the lower contents of chlorophyll in diseased leaves. This clearly inhibited the light-harvesting and photosystem II activity of photosynthesis; however, overexpression of genes related to starch, sucrose and glucose synthesis led to higher contents of these carbohydrates. Meanwhile, transmission electron microscopy images revealed that dense amounts of phytoplasmas accumulated in the sieve elements of diseased petiole phloem, and the structure of the grana and stroma lamellae of chloroplasts in the diseased leaves was destroyed. Phytoplasma infection inhibited photosynthesis and led to abnormal carbohydrate accumulation in the diseased leaves. Furthermore, comparative metabolite analysis indicated that phytoplasma infection also stimulated amino acids and energy metabolisms of the diseased leaves. Continually inhibiting the photosynthetic process and stimulating carbohydrate and energy metabolisms of diseased trees may exhaust their nutrients. Our results highlight the importance of changing host metabolisms during the pathogenic process.


Assuntos
Metabolismo dos Carboidratos , Metabolismo Energético , Fotossíntese , Phytoplasma/patogenicidade , Doenças das Plantas/imunologia , Ziziphus/imunologia , Clorofila/metabolismo , Cloroplastos/ultraestrutura , Modelos Biológicos , Doenças das Plantas/microbiologia , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Folhas de Planta/fisiologia , Folhas de Planta/ultraestrutura , Caules de Planta/imunologia , Caules de Planta/microbiologia , Caules de Planta/fisiologia , Caules de Planta/ultraestrutura , Ziziphus/microbiologia , Ziziphus/fisiologia , Ziziphus/ultraestrutura
12.
J Photochem Photobiol B ; 160: 43-52, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27088508

RESUMO

To evaluate the biological preference of chiral drug candidates for molecular target DNA, the synthesis and characterization of a chiral copper(II) complex (2) of a chiral ligand N,N'-(pyridin-2-ylmethylene) dehydroabietylamine (1) was carried out. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral, emission spectral and viscosity analysis reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. In the absence/presence of ascorbic acid, 1 and 2 cleaved supercoiled pBR322 DNA by single-strand and 2 displayed stronger DNA cleavage ability. In addition, in vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines study show that they exhibited effective cytotoxicity against the tested cell lines, notably, 2 showed a superior cytotoxicity than the widely used drug cisplatin under identical conditions, indicating it has the potential to act as effective anticancer drug. Flow cytometry analysis indicates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis demonstrates that 2 mainly arrested HeLa cells at the S phase. The study represents the first step towards understanding the mode of the promising chiral rosin-derivative based copper complexes as chemotherapeutics.


Assuntos
Antineoplásicos/farmacologia , Cobre/química , Resinas Vegetais/farmacologia , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cristalografia por Raios X , Humanos , Resinas Vegetais/química , Análise Espectral/métodos , Estereoisomerismo , Viscosidade
13.
J Photochem Photobiol B ; 142: 77-85, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25528191

RESUMO

The first chiral trinuclear iron(III) complex [Fe3(µ3-O)(L)6(CH3OH)2(CH3O)]⋅H2O (2) of a natural rosin product dehydroabietic acid (HL, 1) was synthesized and fully characterized. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral (Kb=1.30×10(5)M(-1) (1), 1.40×10(5)M(-1)(2)), emission spectral (KSV=1.19×10(4)M(-1) (1), 1.79×10(4)M(-1) (2)) and viscosity measurements reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a slight higher DNA binding ability. The Stern-Volmer quenching constant (KSV) and corresponding thermodynamic parameters (ΔG, ΔH and ΔS) of the binding processes were determined. The negative ΔH and ΔG values indicate that the binding reactions were exothermic and spontaneous. 1 and 2 were also screened for their cytotoxic ability and 1 demonstrated higher growth inhibition of the selected cancer cells at concentrations of 25µM and 50µM, this result was not identical with their DNA binding ability order. Thus, the involvement of Fe(III) centers had positive effect on DNA binding ability and negative effect on cytotoxicity.


Assuntos
Complexos de Coordenação/química , DNA/química , Compostos Férricos/química , Resinas Vegetais/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dicroísmo Circular , Complexos de Coordenação/metabolismo , Complexos de Coordenação/toxicidade , Cristalografia por Raios X , DNA/metabolismo , Células HeLa , Humanos , Células MCF-7 , Conformação Molecular , Espectrometria de Fluorescência , Estereoisomerismo , Termodinâmica , Viscosidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA