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1.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(7): 708-715, 2024 Jul 15.
Artigo em Chinês | MEDLINE | ID: mdl-39014947

RESUMO

OBJECTIVES: To investigate the expression of CD123 in children with acute lymphoblastic leukemia (ALL) and its effect on the clinical characteristics and prognosis of children with B-lineage acute lymphoblastic leukemia (B-ALL). METHODS: A retrospective analysis was conducted on the clinical data of 251 children with ALL who were admitted to the Department of Hematology and Oncology, Children's Hospital of Kunming Medical University, from December 2019 to June 2022. According to the expression of CD123 at initial diagnosis, the children were divided into CD123+ group and CD123- group, and the two groups were compared in terms of clinical characteristics and treatment outcome. The factors influencing the prognosis were analyzed. RESULTS: Among the 251 children with ALL, there were 146 children (58.2%) in the CD123+ group. The B-ALL group had a significantly higher positive expression rate of CD123 than the acute T lymphocyte leukemia group (P<0.05). Compared with the CD123- group, the CD123+ group had significantly lower peripheral blood leukocyte count and percentage of juvenile cells and a significantly higher proportion of children with high hyperdiploid karyotype or an age of 1-10 years, with a relatively low proportion of children with E2A-PBX1 fusion gene (P<0.05). The multivariate Cox proportional-hazards regression model analysis showed that compared with the >10 years group, the 1-10 years group had a significantly higher overall survival rate (P<0.05), and compared with the high risk group, the moderate risk group had a significantly higher event-free survival rate in children with B-ALL (P<0.05). CONCLUSIONS: CD123 is widely expressed in children with B-ALL, and positive expression of CD123 might be an indicator for good prognosis in children with B-ALL, which is of great significance for evaluating the efficacy of remission induction therapy and survival prognosis of children with B-ALL.


Assuntos
Subunidade alfa de Receptor de Interleucina-3 , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Masculino , Feminino , Criança , Pré-Escolar , Subunidade alfa de Receptor de Interleucina-3/análise , Subunidade alfa de Receptor de Interleucina-3/genética , Prognóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Estudos Retrospectivos , Lactente , Adolescente
2.
Mol Med ; 30(1): 73, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822233

RESUMO

Human malignant pleural mesothelioma (hMPM) is an aggressive, rare disease with a poor prognosis. Histologically, MPM is categorized into epithelioid, biphasic, and sarcomatoid subtypes, with the epithelioid subtype generally displaying a better response to treatment. Conversely, effective therapies for the non-epithelioid subtypes are limited. This study aimed to investigate the potential role of FK228, a histone deacetylase inhibitor, in the suppression of hMPM tumor growth. We conducted a comprehensive analysis of the histological and molecular characteristics of two MPM cell lines, CRL-5820 (epithelioid) and CRL-5946 (non-epithelioid). CRL-5946 cells and non-epithelioid patient-derived xenografted mice exhibited heightened growth rates compared to those with epithelioid MPM. Both CRL-5946 cells and non-epithelioid mice displayed a poor response to cisplatin. However, FK228 markedly inhibited the growth of both epithelioid and non-epithelioid tumor cells in vitro and in vivo. Cell cycle analysis revealed FK228-induced G1/S and mitotic arrest in MPM cells. Caspase inhibitor experiments demonstrated that FK228-triggered apoptosis occurred via a caspase-dependent pathway in CRL-5946 but not in CRL-5820 cells. Additionally, a cytokine array analysis showed that FK228 reduced the release of growth factors, including platelet-derived and vascular endothelial growth factors, specifically in CRL-5946 cells. These results indicate that FK228 exhibits therapeutic potential in MPM by inducing cytotoxicity and modulating the tumor microenvironment, potentially benefiting both epithelioid and non-epithelioid subtypes.


Assuntos
Apoptose , Proliferação de Células , Depsipeptídeos , Mesotelioma Maligno , Mesotelioma , Ensaios Antitumorais Modelo de Xenoenxerto , Humanos , Animais , Mesotelioma Maligno/tratamento farmacológico , Mesotelioma Maligno/patologia , Linhagem Celular Tumoral , Camundongos , Mesotelioma/tratamento farmacológico , Mesotelioma/patologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Depsipeptídeos/farmacologia , Depsipeptídeos/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pleurais/tratamento farmacológico , Neoplasias Pleurais/patologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Feminino , Células Epitelioides/patologia , Ciclo Celular/efeitos dos fármacos
3.
Cogn Neurodyn ; 17(3): 681-694, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37265660

RESUMO

How mild cognitive impairment (MCI) is instantiated in dynamically interacting and spatially distributed functional brain networks remains an unexplored mystery in early Parkinson's disease (PD). We applied a machine-learning technology based on personalized sliding-window algorithm to track continuously time-varying and overlapping subnetworks under the functional brain networks calculated form resting state electroencephalogram data within a sample of 33 early PD patients (13 early PD patients with MCI and 20 early PD patients without MCI). We decoded a set of subnetworks that captured surprisingly dynamically varying and integrated interactions among certain brain lobes. We observed that the master expressed subnetworks were particularly transient, and flexibly switching between high and low expression during integration into a dynamic brain network. This transience was particularly salient in a subnetwork predominantly linking temporal-parietal-occipital lobes, which decreases in both expression and flexibility in early PD patients with MCI and expresses their degree of cognitive impairment. Moreover, MCI induced a regularly interrupted, slow evolution of subnetworks in functional brain network dynamics in early PD at the individual level, and the dynamic expression characteristics of subnetworks also reflected the degree of cognitive impairment in patients with early PD. Collectively, these results provide novel and deeper insights regarding MCI-induced abnormal dynamical interaction and large-scale changes in functional brain network of early PD.

4.
Artigo em Inglês | MEDLINE | ID: mdl-37022414

RESUMO

The early Parkinson's disease (PD) with mild cognitive impairment (ePD-MCI) is a typical non-motor symptom reflected by the brain dysfunction of PD, which can be well depicted by the dynamic characteristics of brain functional connectivity networks. The aim of this study is to determine the unclear dynamic changes in functional connectivity networks induced by MCI in early PD patients. In this paper, the electroencephalogram (EEG) of each subject was reconstructed into the dynamic functional connectivity networks with five frequency bands based on adaptive sliding window method. By evaluating the fluctuations of dynamic functional connectivity and the transition stability of functional network state in ePD-MCI patients compared with early PD without mild cognitive impairment patients, it was found that in the alpha band, the functional network stability of central region, right frontal, parietal, occipital, and left temporal lobes was abnormally increased, and the dynamic connectivity fluctuations in these regions were significantly decreased in ePD-MCI group. In the gamma band, ePD-MCI patients showed decreased functional network stability in the central, left frontal, and right temporal lobes, and active dynamic connectivity fluctuations in the left frontal, temporal, and parietal lobes. The aberrant duration of network state in ePD-MCI patients was significantly negatively correlated with cognitive function in the alpha band, which might pave the way to identify and predict cognitive impairment in early PD patients.

5.
Sci Total Environ ; 857(Pt 1): 159368, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36228786

RESUMO

Soil macropores largely control the water and nutrients transport as well as runoff processes in the soil. Biochar is frequently applied to soils to improve the macropore structure, but the effects remain controversial. To clarify depth-dependent soil macropore characteristics affected by biochar addition, the intact soil cores with a depth of 200 mm were collected from biochar-amended paddy field at addition rates of 0, 24, and 48 t ha-1 (CK, BC1, and BC2, respectively). The two biochar treatments did not change the overall soil pore indices (e.g., macroporosity, pore number, fractal dimension, and circularity), but showed distinct effects at different soil depths. At a soil depth of 0-50 mm, the biochar treatments had higher macroporosity (8.59-8.85 %) than CK (4.94 %) (p < 0.05), but relatively lower pore circularity (0.83-0.84) than CK (0.88) (p < 0.05). The connectivity of biochar treatments (88-97) was 9.5-10.4 times higher than that of CK (9.3). At a soil depth of 100-200 mm, the biochar treatments exhibited lower macroporosity, macropore number, connectivity, and fractal dimension than CK (p < 0.05). The macropore indices (except circularity) of BC1 were relatively higher than those of BC2 in the most soil depths. Whether biochar altered the soil macropore indices depended on the addition rate of biochar and soil depth. The expansion and occupying effects of biochar were dominant at soil depths of 0-50 and 100-200 mm, respectively; and the two effects were stronger in BC1 than in BC2. A combination of the expansion and occupying effects occurred at a soil depth of 50-100 mm. The distinct effects of biochar on soil pore structure at different depths could mitigate methane emission and nutrient runoff loss from the double-rice paddy. Therefore, soil depth-dependent macropore structure should be considered when assessing the influence of biochar on soil properties and the associated environmental effects.


Assuntos
Oryza , Solo , Solo/química , Carvão Vegetal/química , Microbiologia do Solo
6.
Cogn Neurodyn ; 16(2): 309-323, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35401875

RESUMO

To explore the abnormal brain activity of early Parkinson's disease with mild cognitive impairment (ePD-MCI) patients, the study analyzed the dynamic fluctuation of electroencephalogram (EEG) signals and the dynamic change of information communication between EEG signals of ePD-MCI patients. In this study, we recorded resting-state EEG signals of 30 ePD-MCI patients and 37 early Parkinson's disease without mild cognitive impairment (ePD-nMCI) patients. First, we analyzed the difference of the complexity of EEG signals between the two groups. And we found that the complexity in the ePD-MCI group was significantly higher than that in the ePD-nMCI group. Then, by analyzing the dynamic functional network (DFN) topology based on the optimal sliding-window, we found that the temporal correlation coefficients of ePD-MCI patients were lower in the delta and theta bands than those in the ePD-nMCI patients. The temporal characteristic path length of ePD-MCI patients in the alpha band was higher than that of ePD-nMCI patients. In the theta and alpha bands, the temporal small world degrees of ePD-MCI patients were lower than that of patients with ePD-nMCI. In addition, the functional connectivity strength of ePD-MCI patients affected by cognitive impairment was weaker than that of ePD-nMCI patients, and the stability of dynamic functional connectivity network was decreased. This finding may serve as a biomarker to identify ePD-MCI and contribute to the early intervention treatment of ePD-MCI.

7.
ACS Appl Mater Interfaces ; 12(41): 46816-46826, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33001623

RESUMO

Biotissue adhesives and antibacterial materials have great potential applications in wound dressing, implantable devices, and bioelectronics. In this study, stretchable tissue adhesive hydrogels with intrinsic antibacterial properties have been demonstrated by copolymerizing zwitterionic monomers with ionic monomers. The hydrogels are stretchable to about 900% strain and show a modulus of 4-9 kPa. The zwitterionic moieties provide strong dipole-dipole interaction, electrostatic interaction, and hydrogen bonding with the skin surface, and thus show adhesion strength values of 1-4 kPa to skin. Meanwhile, the copolymerized cationic or anionic monomers break the intrinsic electrostatic stoichiometry of the zwitterionic units and thus mediate the electrostatic interactions and the adhesion strength with the surface. The stretchable hydrogels form a robust and compliant (due to low modulus and stretchability) adhesive to skin, rubber, glass, and plastics, and could be repeatedly peeled-off and readhered to the skin. Moreover, the abundant quaternary ammonium (QA) groups in the zwitterionic moieties and the added QA groups endow it outstanding antibacterial properties (>99%). These stretchable tissue adhesive antibacterial hydrogels are promising for wound dressings and implantable devices.


Assuntos
Adesivos/farmacologia , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Hidrogéis/farmacologia , Polieletrólitos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Adesivos/química , Antibacterianos/química , Humanos , Hidrogéis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Tamanho da Partícula , Polieletrólitos/química , Eletricidade Estática , Propriedades de Superfície
8.
J Mater Chem B ; 7(1): 24-29, 2019 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-32254947

RESUMO

Inspired by biosystem, ionic hydrogels have been extensively studied as promising materials for wearable or implantable devices. Herein, we report novel ionic hydrogels that comprise dynamically crosslinked polyzwitterion and physically crosslinked polyvinyl alcohol, which demonstrate excellent mechanical properties, repeatable self-adhesion, and high and linear strain sensitivity. The obtained hydrogels can be directly attached to human skin as sensors to detect or monitor physiological signals.


Assuntos
Adesivos/química , Elastômeros/química , Hidrogéis/química , Dispositivos Eletrônicos Vestíveis , Íons/química , Álcool de Polivinil/química
9.
J Mater Chem B ; 7(16): 2619-2625, 2019 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32254994

RESUMO

Intelligent hydrogels responsive to external stimuli have been widely studied due to their great potentials for applications in artificial muscles, soft robotics, sensors and actuators. However, the weak mechanical properties, narrow response range, and slow response speed of many responsive hydrogels have hindered practical applications. In this paper, tough multi-responsive hydrogels were synthesized by using vinyl-functionalized triblock copolymer micelles as macro-crosslinkers and N-isopropyl acrylamide (NIPAM) and acrylamide (AAm) or 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 2-acrylamido-2-methyl-1-propane-sulfonic acid (AMPS) as monomers. The P(NIPAM-co-AAm) hydrogels presented tensile strength of up to 1.6 MPa and compressive strength of up to 127 MPa and were tunable by changing their formulations. Moreover, the lower critical solution temperature (LCST) of the thermosensitive hydrogels was manipulated in a wide range by changing the molar ratio of NIPAM to AAm. Responsive hydrogel bilayers were fabricated through a two-step synthesis. A second layer of P(DMAEMA-co-AMPS) was synthesized on the first P(NIPAM-co-AAm) layer to obtain a bilayer hydrogel, which was responsive to temperature, pH and ionic strength changes to undergo fast and reversible shape transformation in a few minutes. This kind of strong and tough multi-responsive hydrogel device has broad prospects in soft actuators.


Assuntos
Hidrogéis/química , Acrilamidas/química , Alcanossulfonatos/química , Força Compressiva , Metacrilatos/química , Micelas , Polímeros/química , Resistência à Tração
10.
ACS Appl Mater Interfaces ; 11(3): 3506-3515, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30592203

RESUMO

It is desired to create skin strain sensors composed of multifunctional conductive hydrogels with excellent toughness and adhesion properties to sustain cyclic loadings during use and facilitate the electrical signal transmission. Herein, we prepared transparent, compliant, and adhesive zwitterionic nanocomposite hydrogels with excellent mechanical properties. The incorporated zwitterionic polymers can form interchain dipole-dipole associations to offer additional physical cross-linking of the network. The hydrogels show a high fracture elongation up to 2000%, a fracture strength up to 0.27 MPa, and a fracture toughness up to 2.45 MJ/m3. Moreover, the reversible physical interaction imparts the hydrogels with rapid self-healing ability without any stimuli. The hydrogels are adhesive to many surfaces including polyelectrolyte hydrogels, skin, glasses, silicone rubbers, and nitrile rubbers. The presence of abundant zwitterionic groups facilitates ionic conductivity in the hydrogels. The combination of these properties enables the hydrogels to act as strain sensors with high sensitivity (gauge factor = 1.8). The strategy to design the tough, adhesive, self-healable, and conductive hydrogels as skin strain sensors by the zwitterionic nanocomposite hydrogels is promising for practical applications.


Assuntos
Técnicas Biossensoriais , Condutividade Elétrica , Hidrogéis/química , Nanocompostos/química , Adesivos/química , Humanos , Íons/química , Polímeros/química , Pele/diagnóstico por imagem , Pele/lesões , Entorses e Distensões/diagnóstico , Entorses e Distensões/patologia
11.
ACS Appl Mater Interfaces ; 10(48): 41724-41731, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30387979

RESUMO

Responsive hydrogel actuators have promising applications in diverse fields. Most hydrogel actuators are limited by slow actuation or shape transformations. This work reports on snap-buckling motivated jumping of thermoresponsive hydrogel bilayers. The bilayers are composed of poly(NIPAM- co-DMAPMA)/clay hydrogel with different lower critical solution temperatures in each layer, and thus undergo slow reversible curling/uncurling at temperature changes. The gels are adhesive to numerous materials including aluminum. The adhesion between the gels and an aluminum ratchet is utilized to constrain the thermoresponsive deformation of the bilayers to store elastic energy. When the accumulated elastic energy overwhelms the gel-aluminum adhesion, snap-buckling takes place to abruptly release the accumulated energy, which motivates the bilayer to jump. The jumping direction, start time, height, and distance are controlled by the geometry of the bilayers or the ratchet. This work paves a novel way for the rapid actuation of responsive hydrogels in a controlled manner and may stimulate the development of novel hydrogel devices.

12.
Dalton Trans ; 43(37): 13924-31, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25111133

RESUMO

Intensely luminescent 1,8-naphthyridine-BF2 complexes 1-9 containing terminal bidentate N^N^O and/or N^C^O groups are synthesized and structurally characterized by X-ray diffraction, electrospray ionization mass spectrometry, (1)H and (19)F NMR spectroscopy and elemental analysis. Complexes 1-4 are synthesized from 2-acetamino-1,8-naphthyridine derivatives by a facile route. Selective bonding modes and the chemical stability of complexes 5 and 6 obtained by reacting BF3·Et2O with 1,8-naphthyridine derivatives bearing dual-functional groups (N^C^O and N^N^O) are investigated by crystal structure analysis and time-dependent density functional theory calculations. The products containing a BF2 core bound to a N^C^O chelating group are energetically favorable and can expand the range of derivatives by substitution at the 2-position. In this regard, a free -NH2 group at the 2-position of complex 7 obtained from 5 can be functionalized under a variety of pH conditions to generate complexes 8 and 9, which bear flexible coordination arms that can be used to recognize certain transition metals. The photophysical properties of the complexes are examined in solution and solid state at room temperature. Compared with those of the starting naphthyridine-based compounds, the naphthyridine-BF2 complexes display desirable light-absorbing properties and intense solution and solid-state emission with large Stokes shifts. Complex 4 in solution exhibited an emission quantum yield of 0.98. In complexes 5-9, the binding sites for the BF2 core change from N^N^O to N^C^O, which leads to red shifts of absorption and emission, excellent chemical stability and high emission quantum yields.

13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(7): 1298-302, 2006 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-17020044

RESUMO

The mechanism of the interaction between hydrazide-podophyllic (HDPP) metal (Me) complexes and calf thymus (ct) DNA in Tris buffer (pH 7.08) was studied by viscosity measurements, electronic absorption, gel electrophoresis, and ethidium bromide (EB) fluorescence spectroscopy. The results from varied experiments show that the intensity of the maximal absorption peaks from absorption spectra is weakened in the presence of DNA compared with that in the absence of DNA. Meanwhile, DNA can remarkably quench the emission intensity of the complex Me-HDPP system. The Me-HDPP complexes can increase the viscosity of ct DNA slightly and catalyze the cleavage of super coiled pBR322 DNA to the nicked form. The complexes of Ni-HDPP and Co-HDPP can be bound to ct DNA mainly by interaction, while the partial interaction of Zn-HDPP and ct DNA is the major modes. The binding constant of Me-HDPP complexes with ct DNA was determined.


Assuntos
DNA/química , DNA/metabolismo , DNA Super-Helicoidal/química , Hidrazinas/química , Plasmídeos/química , Podofilina/química , Espectrometria de Fluorescência
14.
J Inorg Biochem ; 100(10): 1685-91, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16876869

RESUMO

Absorption, fluorescence spectral, cyclic voltammetry and agarose gel electrophoresis studies have been carried out on the interaction of Ni(II) complex with all-trans retinoic acid ([Ni(RA)(2)(H(2)O)(2)] * H(2)O) with DNA. The results indicate that the [Ni(RA)(2)(H(2)O)(2)] * H(2)O can more effectively promote the cleavage of plasmid DNA than that of all-trans retinoic acid (HRA) and Ni(II) at physiological pH and temperature, which may be one of the reasons why the inhibitory effect of [Ni(RA)(2)(H(2)O)(2)] * H(2)O on the human bladder line EJ cells is much greater than that of retinoic acid. It was found that the process of plasmid DNA cleavage was sensitive to ionic strength and pH, however, these radical scavengers almost had no effect on the DNA cleavage reaction. The above results suggested that the cleavage of plasmid DNA by [Ni(RA)(2)(H(2)O)(2)]* H(2)O did not produce diffusible hydroxyl radicals via the Fenton reaction. The results of UV-absorption studies and fluorescence characterization of the interaction of [Ni(RA)(2)(H(2)O)(2)] * H(2)O with Calf thymus DNA show that the [Ni(RA)(2)(H(2)O)(2)] * H(2)O binds to DNA mainly in an intercalating mode.


Assuntos
Antineoplásicos/metabolismo , DNA/metabolismo , Níquel/metabolismo , Tretinoína/metabolismo , DNA/química , Concentração de Íons de Hidrogênio , Níquel/química , Concentração Osmolar , Plasmídeos/genética , Espectrometria de Fluorescência , Temperatura , Fatores de Tempo , Tretinoína/química
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(5): 941-3, 2006 May.
Artigo em Chinês | MEDLINE | ID: mdl-16883874

RESUMO

The interaction between the metal complex of hydrazide of podophyllic acid and calf thymus (CT) DNA was studied by using absorption spectra, fluorescence spectra and DNA heat denaturation. It was found that the intensity of the maximal absorption peaks from absorption spectra is weakened in the presence of the metal complex of hydrazide of podophyllic acid compared with that in the absence of the metal complex. All the experimental results show that the intercalation mode was proved to exist between HDPP-Ni complexes and CT DNA.


Assuntos
Antibacterianos/química , DNA/química , Podofilotoxina/análogos & derivados , Animais , Bovinos , Podofilotoxina/química , Espectrofotometria Ultravioleta
16.
J Am Chem Soc ; 126(8): 2280-1, 2004 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-14982412

RESUMO

Four 3-D coordination polymers of lanthanide with a tetra(amino acid) ligand, 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetrapropionic acid (H4L, 1), were synthesized. The structure of the Gd(III) complex was characterized. The fluorescence of the Eu(III) complex can be modulated by Ag+.


Assuntos
Elementos da Série dos Lantanídeos/química , Polímeros/química , Prata/química , Compostos Aza/síntese química , Compostos Aza/química , Cátions , Cristalografia por Raios X , Fluorescência , Medições Luminescentes , Polímeros/síntese química , Propionatos/síntese química , Propionatos/química , Solubilidade , Água/química
17.
J Inorg Biochem ; 91(3): 470-4, 2002 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-12175939

RESUMO

Absorption, fluorescence spectral and viscometric studies have been carried out on the interaction of Morin (2',3,4',5,7-pentahydroxyflavone, ) and its Cu complex, CuL(2) x 2H(2)O [L=Morin (2'-OH group deprotonated), ] with calf thymus DNA. CuL(2) shows different spectral characteristics from that of Morin in the presence of DNA. Increasing fluorescence is seen for CuL(2) with DNA addition whereas decreased fluorescence is observed for Morin. Quenching fluorescence is observed for the DNA-EB system when CuL(2) is added whereas slightly quenched fluorescence is seen for the DNA-EB system with Morin addition. The relative viscosity of DNA and the DNA-EB system increases with the addition of CuL(2.) Hypochromism and a smaller shift are observed in the UV-visible spectra of CuL(2) in the presence of DNA and the denatured temperature of DNA is decreased in the presence of CuL(2). The above results suggested that Morin and CuL(2) can both bind to DNA, but the binding mode is different. The complex binds to DNA mainly by intercalation, while Morin binds in a nonintercalating mode.


Assuntos
Antioxidantes/química , Cobre/química , DNA/química , Flavonoides/química , Animais , Bovinos , Conformação de Ácido Nucleico , Espectrometria de Fluorescência , Timo
18.
Inorg Chem ; 41(8): 2188-92, 2002 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-11952373

RESUMO

Two new nonanuclear lanthanide(III)-copper(II) complexes of macrocyclic oxamide [NaPr(2)(CuL)(6)(H(2)O)(6)](ClO(4))(6)Cl small middle dot6H(2)O (1) and [NaNd(2)(CuL)(6)(H(2)O)(6)](ClO(4))(6)Cl small middle dot8H(2)O (2) have been synthesized and characterized by means of elemental analysis, IR, and electronic spectra, where L = 1,4,8,11-tetraazacyclotradecanne-2,3-dione. The crystal structures of the two complexes have been determined. The structures of 1 and 2 consist of nonanuclear cations, perchlorate and chloride anions, and water molecules. In the two complexes, each copper(II) ion is connected to lanthanide(III) ion via the exo-cis oxygen atoms of the oxamido macrocyclic ligands, resulting in a tetranuclear subunit. The sodium ion links two tetranuclear subunits via the exo oxygen atoms of the oxamido macrocyclic ligands which results in a novel nonanuclear complex. The magnetic properties of the two complexes have been investigated. Preliminary treatment of the magnetic data by considering Ln(III) as free ion cannot give reasonable results, and accurate models involving both the orbital contribution and ligand field effect have to be developed.

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