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1.
Am J Transl Res ; 14(3): 2123-2132, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35422926

RESUMO

Background: Colorectal cancer (CRC) represents a major health concern that can be screened for by the fecal immunochemical test (FIT), which detects blood in the stool. CRC detection sensitivity for hemoglobin (Hb) combined with transferrin (Tf) is higher than for hemoglobin alone. Methods: We developed a europium fluorescent microsphere-based quantitative lateral flow immunochromatography strip to detect fecal Hb and Tf. Performance was tested using fecal samples from 51 patients with CRC and 122 normal subjects. Test strips were generated using paired mouse anti-human Hb and mouse anti-human Tf monoclonal antibodies and tested using standard Hb and Tf samples. Fluorescence was observed at 365 nm and quantitatively measured using a portable fluorescent strip reader. Results: At cutoff values of 100 ng/mL (10 µg/g feces) and 25 ng/mL (2.5 µg/g feces) for Hb and Tf, respectively, the positive rates for Hb, Tf, and Hb+Tf in normal subjects were 6.56%, 5.74%, and 10.66%, respectively, compared to 88.24%, 64.71%, and 94.12% in patients with CRC. The sensitivity and specificity of the FIT combined detection technique were 87.5% and 89.2%, respectively, and the area under the curve (AUC) was 0.92. The sensitivity, specificity, and AUC for the Tf assay were 63.8%, 68.4%, and 0.759, respectively, and those for Hb testing were 69.7%, 70.2%, and 0.774, respectively. The AUC for Hb+Tf was significantly higher than those for Tf or Hb alone (P < 0.001). Conclusions: Fluorescent microsphere-based immunochromatographic strips sensitively detect fecal Hb and Tf, and sensitivity and specificity are improved for Hb+Tf. This system represents a rapid and portable alternative for on-site early CRC screening.

2.
J Mol Model ; 27(2): 29, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33415409

RESUMO

The interactions of nucleobase with Au20 cluster were studied utilizing density functional theory (DFT). We find that the nucleobases were attached with Au20 through Au-N or Au-O bonds. The orders of calculated adsorption energy are cytosine > adenine > guanine > thymine. The maximum adsorption energy is - 0.787 eV which belongs to the adsorption of cytosine on Au20 cluster. Our calculations show that the HOMO-LUMO gaps of Au20 are significantly decreased by the nucleobase adsorption, suggesting the potential detection for nucleobases. The interactions between Au20 and nucleobases are revealed through the QTAIM analysis. The NBO analysis was investigated for the electron transfer of donor-acceptor of all types of complexes. The IR and UV-vis spectra were simulated for the further identification in the experiment.


Assuntos
Teoria da Densidade Funcional , Ouro/química , Purinas/química , Pirimidinas/química , Adsorção , Modelos Moleculares , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Termodinâmica
3.
ACS Omega ; 4(7): 12376-12384, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31460355

RESUMO

A novel magnetic nanocomposite of Ni x Mn1-x Fe2O4/carbonized chaff (x = 0.3, 0.5, and 0.7) has been synthesized successfully via the co-carbonization and hydrothermal method. The microstructure, morphology, complex permittivity and permeability, and microwave absorbing properties were systematically studied by X-ray diffraction, scanning electron microscopy, and a vector network analyzer. Compared to the pure Ni0.5Mn0.5Fe2O4 NPs, the Ni0.3Mn0.7Fe2O4/carbonized chaff-N2 composite exhibits an optimal microwave absorption property at 4 mm as the mass percent of carbonized chaff is 10 wt %, the maximum reflection loss of which can reach -14.58 dB at 1.91 GHz with the -10 dB frequency bandwidth in the range of 1.46-2.41 GHz (0.95 GHz). The enhanced electromagnetic wave absorbing performance is ascribed to the good synergistic effect among laminated structures, better impedance matching condition, strong natural resonance loss, Debye dipolar relaxation to some extent, and so forth. Most importantly, this study provides a novel way to prepare easily degradable, environment-friendly, and high-efficiency electromagnetic wave absorbers by utilizing the structural property of renewable biomaterials.

4.
J Cancer ; 9(9): 1568-1574, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29760794

RESUMO

Traditional Chinese medicine has been widely used in cancer treatment in China. Yangyin Fuzheng Decoction is a traditional Chinese compound medicine, composed of 12 traditional Chinese herbs. This study aimed to investigate anti-tumor activity and the underlying mechanisms of Yangyin Fuzheng Decoction combined with cisplatin in the treatment of lung cancer. We established lung cancer model in C57BL/6 mice injected with mouse Lewis lung cancer cells. Our results demonstrated that Yangyin Fuzheng Decoction treatment increased necrotic area in tumor tissue, and significantly enhanced the recruitment of inflammatory cells into the tumor. In addition, Yangyin Fuzheng Decoction treatment enhanced the anti-tumor efficacy of cisplatin and partially recovered mouse body weight loss caused by cisplatin treatment. Mechanistically, we found that Yangyin Fuzheng Decoction upregulated the expression of pro-apoptotic proteins p53 and Bax and suppressed the expression of anti-apoptotic protein Bcl-2. Combined treatment of Yangyin Fuzheng Decoction and cisplatin further increased p53 and Bax levels and suppressed Bcl-2 level. Taken together, these data suggest that Yangyin Fuzheng Decoction could synergistically enhance the apoptotic signaling in cancer cells during chemotherapy. In addition, it has health improving and immune response enhancing effects. Yangyin Fuzheng Decoction could be a promising adjunct agent for lung cancer chemotherapy.

5.
Sci Rep ; 8(1): 1940, 2018 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-29386581

RESUMO

The Saturn-like charge-transfer complex Li4&B36, which was recently predicted with extensive first-principles theory calculations, were studied as a candidate for hydrogen storage material in the present work. The bonding characters of Li-B, B-B and Li-H2 bonds were revealed by the quantum theory of atoms in molecules (QTAIM). Each Li atom in Li4&B36 cluster can bind six H2 molecules at most, which results into the gravimetric density of 10.4%. The adsorption energies of H2 molecules on Li4&B36 cluster are predicted in the range of 0.08-0.14 eV at the wB97x level of theory.

6.
Int J Mol Sci ; 17(4): 414, 2016 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-27077844

RESUMO

The interaction natures between Pu and different ligands in several plutonyl (VI) complexes are investigated by performing topological analyses of electron density. The geometrical structures in both gaseous and aqueous phases are obtained with B3LYP functional, and are generally in agreement with available theoretical and experimental results when combined with all-electron segmented all-electron relativistic contracted (SARC) basis set. The Pu- O y l bond orders show significant linear dependence on bond length and the charge of oxygen atoms in plutonyl moiety. The closed-shell interactions were identified for Pu-Ligand bonds in most complexes with quantum theory of atoms in molecules (QTAIM) analyses. Meanwhile, we found that some Pu-Ligand bonds, like Pu-OH(-), show weak covalent. The interactive nature of Pu-ligand bonds were revealed based on the interaction quantum atom (IQA) energy decomposition approach, and our results indicate that all Pu-Ligand interactions is dominated by the electrostatic attraction interaction as expected. Meanwhile it is also important to note that the quantum mechanical exchange-correlation contributions can not be ignored. By means of the non-covalent interaction (NCI) approach it has been found that some weak and repulsion interactions existed in plutonyl(VI) complexes, which can not be distinguished by QTAIM, can be successfully identified.


Assuntos
Compostos Organometálicos/química , Plutônio/química , Elétrons , Ligantes , Modelos Moleculares , Conformação Molecular , Teoria Quântica , Água/química
7.
Dalton Trans ; 43(14): 5574-9, 2014 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-24548947

RESUMO

A high-stability icosahedral cluster (Ta12(2+)) with spherical aromaticity was found within a DFT framework. The spherical aromaticity of the icosahedral Ta12(2+) cluster was confirmed by a high symmetry, a short bond length, a high vibrational frequency, a large HOMO-LUMO gap and negative NICS(0) values. The icosahedral Ta12(2+) cluster is the first example of a bare metal cluster with a total of 58 valence electrons. The electron density topological analyses (QTAIM and ELF) indicate that three-center shared interactions exist in the icosahedral structure. The IR and absorption spectra were theoretically simulated as a convenient way to confirm the existence of the icosahedral structure in further experiments.

8.
J Chem Phys ; 136(9): 094311, 2012 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-22401444

RESUMO

The low-lying structures of tantalum cluster cations up to n = 16 are investigated using hybrid HF/density functional theory (DFT) functionals (B3P86) in conjunction with relativistic effective core potential and corresponding basis set. The vibrational spectra of tantalum cluster cations are simulated with one empirical scaling factor of 0.943, and compared to the experimental ones [P. Gruene, A. Fielicke, G. Meijer, J. Chem. Phys. 127, 234307 (2007)]. By assigning the vibrational peaks of experimental spectra, the favored geometries actually existing in the molecular beam are obtained for several studied clusters. Based on the favored geometries, the relative stabilities, spin magnetic moments, and electronic dipole moments are determined. Furthermore, spin-related indices (ω(s) (±)) are computed and found to be good linear correlation with vertical lower-upper energy gap.

9.
J Phys Chem A ; 114(49): 12825-33, 2010 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-21087062

RESUMO

The structural, electronic, and magnetic properties of iridium clusters with sizes of n = 2-15 are investigated by employing the generalized gradient approximation of density functional theory. Simple cube evolution pattern is revealed for Ir(2-15) clusters, as predicted by previous reports. It is remarkable that for Ir(10), Ir(11) clusters, new generated isomers with higher stabilities relative to those reported in previous studies are obtained. The even-sized clusters are more stable than the odd-sized species. The Ir-Ir bonds in the cubic Ir(8) and Ir(12) clusters, which are considered as the basic units in the structural evolution present covalent character. Starting from n = 8, the magnetic moments of Ir(n) clusters decrease sharply. The moments of magnetic clusters show 5d characters. The reactive site selectivity of studied clusters with n = 5-15 is analyzed with condensed Fukui function. The capped atoms in certain clusters (Ir(9), Ir(10), Ir(11), and Ir(13)) generally show extraordinary activity for both nucleophilic and electrophilic attack.

10.
J Chem Phys ; 131(4): 044313, 2009 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-19655873

RESUMO

The geometrical and electronic structures of W(n) (n=2-16) clusters are investigated within the framework of a gradient-corrected density functional theory. The close-packed configurations are preferred for small tungsten clusters up to n=16. The most energetic favorable structures of W(14), W(15), and W(16) clusters, exhibiting similar electronic band structures, are all formed based on body centered cubic (bcc) unit. The clusters with size of n=8, 12, and 15 are found to be more stable with respect to their respective neighbors. The analyses of atomic orbit projected density of states and highest occupied molecular orbital, lowest unoccupied molecular orbital isosurfaces indicate that 5d electrons play a dominant role in the chemical activities of tungsten clusters. The clearly s-d hybridizations are primary presented in bonding W atoms of smaller clusters, as the cluster sizes increase, the 6p orbitals are gradually involved in chemical bonding. Our calculated vertical ionization potentials (VIPs) indicate that the W(8) and W(12) clusters correspond to the high VIPs. The vertical electron affinities are slightly underestimated in our investigation, but follow the trends of experimental data in principle.

11.
Ai Zheng ; 28(7): 685-90, 2009 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-19624892

RESUMO

BACKGROUND AND OBJECTIVE: Metastasis of lung cancer is the leading cause of disease progression and treatment failure. Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) are related to the metastasis of lung cancer via regulating the degradation of extracellular matrix. This study was to observe the impacts of cisplatin (DDP) on the expression of MMP-9 and TIMP-1 in Lewis lung cancer, and explore their correlations and roles in metastasis. METHODS: Lewis lung cancer model was established in C57BL/6 mice. DDP group was given intraperitoneal DDP injection, and compared with normal control and tumor-bearing groups. The expression of MMP-9 and TIMP-1 were determined by ELISA in serum and detected by immunohistochemistry in tumor tissues. RESULTS: The inhibition rates of tumor growth and metastasis were 41.2% and 39.0% in DDP group, respectively. The positive rates of MMP-9 and TIMP-1 were 100% in tumor-bearing group, and their serum concentrations were significantly higher in tumor-bearing group than in normal control group (P<0.05). Serum concentrations of MMP-9 and TIMP-1, and positive rate of MMP-9 were all significantly lower in DDP group than in tumor-bearing group (P<0.05). Serum concentration of MMP-9 and positive rates of MMP-9 and TIMP-1 were positively correlated to tumor weight (r=0.665, 0.749 and 0.615, all P<0.05) and lung metastasis (r=0.668, 0.545 and 0.664, all P<0.05). MMP-9 expression was positively correlated to TIMP-1 expression both in serum and tumor (r=0.617 and 0.695, all P<0.05). The ratio of sMMP-9/TIMP-1 became a constant in normal distribution, with a mean of 1.72. CONCLUSIONS: Both MMP-9 and TIMP-1 are highly expressed in Lewis lung cancer, correlated to tumor invasion and metastasis. DDP may suppress tumor metastasis via down-regulating the expression of MMP-9 and TIMP-1 in serum and tumor.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Lewis/metabolismo , Cisplatino/farmacologia , Metaloproteinase 9 da Matriz/metabolismo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Animais , Carcinoma Pulmonar de Lewis/sangue , Carcinoma Pulmonar de Lewis/patologia , Regulação para Baixo , Feminino , Masculino , Metaloproteinase 9 da Matriz/sangue , Camundongos , Camundongos Endogâmicos C57BL , Metástase Neoplásica , Inibidor Tecidual de Metaloproteinase-1/sangue , Carga Tumoral/efeitos dos fármacos
12.
Methods Mol Med ; 128: 225-30, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17071999

RESUMO

Currently, there is a critical need to develop high-throughput, low-cost, and accurate methods for genotyping of single-nucleotide polymorphisms (SNPs). The matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometrically based technique represents a new promising approach to SNP analysis. We have developed a new MALDI-TOF-based mini-sequencing assay, termed "VSET," for genotyping of SNPs. In this assay, specific fragments of genomic DNA containing the SNP site(s) are first amplified, followed by mini-sequencing in the presence of three ddNTPs and the fourth nucleotide in the deoxy form. In this way, the primer is extended by only one base from one allele, whereas it is typically extended by two bases from another allele. The products are then analyzed using MALDI-TOF mass spectrometry. The genotype of the SNP site is identified based on the number of nucleotides added.


Assuntos
Polimorfismo de Nucleotídeo Único/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Análise Mutacional de DNA/métodos , Genótipo , Humanos , Reação em Cadeia da Polimerase
13.
Clin Cancer Res ; 12(2): 454-9, 2006 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-16428486

RESUMO

PURPOSE: Mutations in mononucleotide repeat sequence (MRS) are good indicators of high-frequency microsatellite instability (MSI-H) cancers, but it has been a challenge to detect such mutations in a large background of wild-type DNA; as in this setting, PCR errors often generate false positive mutant alleles. In this study, we developed a general strategy, referred to as probe clamping primer extension-PCR (PCPE-PCR), to detect MRS alterations in a large background of wild-type DNA. EXPERIMENTAL DESIGN: In PCPE-PCR, genomic DNA is first subjected to PCPE, in which mutant single-strand DNA molecules are preferentially produced. Next, genomic DNA is removed to enrich for the mutant DNA fraction. Thereafter, PCR is carried out using the remaining single-strand DNA molecules as templates. Finally, the PCR products are analyzed to reveal the MSI-H status. In this study, the sensitivity of this new method was first examined by spiking mutant DNA into wild-type DNA at specific ratios followed by studying whether this method is applicable to fecal DNA testing. RESULTS: We showed that PCPE-PCR could detect both mutated BAT26 and transforming growth factor-beta-RII (A)10 markers in the presence of 500-fold excess of normal DNA and that as few as three copies of mutated DNA could be detected. In addition, we showed that this technology could detect MSI-H colorectal cancer by fecal DNA analysis. CONCLUSION: PCPE-PCR is sensitive. In addition, PCPE-PCR is simple and amendable to a cost-effective and high-throughput screening operation. This technology may be applicable to noninvasive screening of MSI-H cancer.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , DNA de Neoplasias/análise , Neoplasias do Endométrio/genética , Instabilidade Genômica , Repetições de Microssatélites/genética , Acetiltransferases/genética , Proteínas de Bactérias/genética , Pareamento Incorreto de Bases/genética , Neoplasias Colorretais/diagnóstico , Neoplasias do Endométrio/diagnóstico , Fezes/química , Feminino , Variação Genética , Humanos , Mutação , Reação em Cadeia da Polimerase/métodos , Proteínas Serina-Treonina Quinases , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Células Tumorais Cultivadas
14.
Rapid Commun Mass Spectrom ; 17(20): 2354-60, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14558138

RESUMO

A new sample preparation procedure has been developed to improve the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) analysis of low-concentration oligonucleotides. In this method, a few microL of the oligonucleotide solutions are first dispensed and allow drying and shrinking to a small spot on an anchoring target. Thereafter, a small volume (0.1 microL) of the saturated 3-hydroxypicolinic acid (3-HPA) solution is added to the top of the shrunk oligonucleotide spot. It is found that the sample prepared by this procedure is more homogenous and substantially reduces the need to search for 'sweet' spots. Importantly, the increased shot-to-shot and sample-to-sample reproducibility makes it possible to perform high-throughput and quantitative analysis. We demonstrated that this procedure allowed the robust detection of oligonucleotides at a level of 0.01 microM and mini-sequencing products produced using only 50 fmol of the extension primer.


Assuntos
Oligonucleotídeos/análise , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Humanos , Oligonucleotídeos/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Nat Biotechnol ; 20(2): 186-9, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11821866

RESUMO

Mutations are important markers in the early detection of cancer. Clinical specimens such as bodily fluid samples often contain a small percentage of mutated cells in a large background of normal cells. Thus, assays to detect mutations leading to cancer need to be highly sensitive and specific. In addition, they should be possible to carry out in an automated and high-throughput manner to allow large-scale screening. Here we describe a screening method, termed PPEM (PNA-directed PCR, primer extension, MALDI-TOF), that addresses these needs more effectively than do existing methods. DNA samples are first amplified using peptide nucleic acid (PNA)-directed PCR clamping reactions in which mutated DNA is preferentially enriched. The PCR-amplified DNA fragments are then sequenced through primer extension to generate diagnostic products. Finally, mutations are identified using matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. This method can detect as few as 3 copies of mutant alleles in the presence of a 10,000-fold excess of normal alleles in a robust and specific manner. In addition, the method can be adapted for simultaneous detection of multiple mutations and is amenable to high-throughput automation.


Assuntos
Análise Mutacional de DNA , DNA/genética , Mutação , Neoplasias/genética , Alelos , Códon , Genes p53/genética , Humanos , Neoplasias Pulmonares/genética , Reação em Cadeia da Polimerase , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
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