RESUMEN

An alternative catalytic method was employed using the reduction of Pd ions on the surface of cetyltrimethylammonium bromide (CTAB) treated laponite to initiate the electroless plating of copper; the deposition features of the Pd nanoparticles produced were investigated in detail. Results indicated intercalation and reduction of Pd nanoparticles occurred at room temperature and involved interaction between the laponite and the cetyltrimethylammonium cationic templates. Organic species and amount on laponite were optimized to adjust silicate platelet interlayer distances and platelet organophilic properties. Intercalation of Pd nanoparticles occurred between the magnesium silicate layers of laponite and this was dependent on pre-treatment and impregnation times. As impregnation is a method of producing heterogeneous catalysts, we considered Pd nanoparticles on laponite templates could catalyze the electroless deposition of Cu to initiate metallization. Cu films fabricated on laponite templates exhibited excellent surface roughness (˜1.7 nm) and low resistivity (˜3.42 µΩ). The devised approach enabled the facile formation of a network suitable for Cu metallization without causing substrate damage and produced metal surfaces with excellent flatness and resistivity.

RESUMEN

Copper has unique properties, such as low electrical resistivity, that are exploited in a number of applications, including an interconnect layer in integrated circuits and microelectronic devices. Etching techniques are essential for the fabrication of fine structures, devices, and circuits. This article addresses the methods of copper etching with an emphasis on approaches using ferric nitrate. Potentiodynamic polarization tests using benzotriazole as an inhibitor showed that ferric nitrate has higher inhibition efficiency than conventional etchants. This is because benzotriazole in a ferric nitrate solution is adsorbed on the copper surface to a greater extent than in a ferric chloride and cupric chloride solution, as confirmed by Fourier transform infrared analysis. Quantitative atomic force microscopy characterization showed that good surface quality with significantly lower surface roughness can be obtained from a copper film etched in a ferric nitrate solution, which has potential use in microelectronics manufacturing.

RESUMEN

The illuminated current-voltage characteristics of Cu(In,Ga)(S,Se)2 (CIGSSe) thin film solar cells fabricated using two different buffer layer processes: chemical bath deposition (CBD) and atomic layer deposition (ALD) were investigated. The CIGSSe solar cell with the ALD buffer showed comparable conversion efficiency to the CIGSSe solar cell with CBD buffer but lower shunt resistance even though it showed lower point shunt defect density as measured in electroluminescence. The shunt paths were investigated in detail by capturing the high-resolution dark lock-in thermography images, resolving the shunt resistance contributions of the scribing patterns (P1, P3), and depth profiling of the constituent elements. It was found that the concentration of Na from the soda-lime glass substrate played a key role in controlling the shunt paths. In the ALD process, Na segregated at the surface of CIGSSe and contributed to the increase in the shunt current through P1 and P3, resulting in a reduction in the fill factor of the CIGSSe solar cells.

RESUMEN

The spin-coating method, which is widely used for thin film device fabrication, is incapable of large-area deposition or being performed continuously. In perovskite hybrid solar cells using CH(3)NH(3)PbI(3) (MAPbI(3)), large-area deposition is essential for their potential use in mass production. Prior to replacing all the spin-coating process for fabrication of perovskite solar cells, herein, a mesoporous TiO(2) electron-collection layer is fabricated by using the electro-spray deposition (ESD) system. Moreover, impedance spectroscopy and transient photocurrent and photovoltage measurements reveal that the electro-sprayed mesoscopic TiO(2) film facilitates charge collection from the perovskite. The series resistance of the perovskite solar cell is also reduced owing to the highly porous nature of, and the low density of point defects in, the film. An optimized power conversion efficiency of 15.11% is achieved under an illumination of 1 sun; this efficiency is higher than that (13.67%) of the perovskite solar cell with the conventional spin-coated TiO(2) films. Furthermore, the large-area coating capability of the ESD process is verified through the coating of uniform 10 × 10 cm(2) TiO(2) films. This study clearly shows that ESD constitutes therefore a viable alternative for the fabrication of high-throughput, large-area perovskite solar cells.

RESUMEN

A permeability- and surface-energy-controllable polyurethane acrylate (PUA) mold, a "capillary-force material (CFM)" mold, is introduced for capillary-force lithography (CFL). In CFL, the surface energy and gas permeability of the mold are crucial. However, the modulation of these two main factors at a time is difficult. Here, we introduce new CFM molds in which the surface energy and permeability can be modified by controlling the degree of cross-linking of the CFM. As the degree of cross-linking of the CFM mold increases, the surface energy and air permeability decrease. The high average functionality of the mold material makes it possible to produce patterns relatively finely and rapidly due to the high rate of capillary rise and stiffness, and the low functionality allows for patterns to form on a curved surface with conformal contact. CFMs with different functionality and controllable-interfacial properties will extend the capabilities of capillary force lithography to overcome the geometric limitations of patterning on a scale below 100 nm and micro- and nanopatterning on the curved region.

RESUMEN

We used genomic sequencing of Korean subjects to identify the uncoupling protein-1 (UCP1) polymorphism -412A>C (rs3811787 in the dbSNP database). This study is the first to associate this polymorphism with a human phenotype. The frequency of the major A allele was 0.53 and that of the minor C allele was 0.47. The -412A>C polymorphism was not linked to the well-known -3826A>G (rs1800592; mid R:D'mid R:=0.60 and r(2)=0.33), yielding four predicted haplotypes from these two polymorphisms. We associated -412A>C, -3826A>G and their haplotypes with computed tomography-measured body fat areas from 367 Korean female subjects. The G allele of -3826A>G and the C allele of -412A>C were significantly associated with larger areas of abdominal subcutaneous fat in a dominant model (p=0.001 and p=0.0004, respectively); combining them together (ht2[GC]) enhanced this significance (p=0.00005). In contrast, presence of the A allele in both polymorphisms (ht1[AA]) was significantly associated with smaller areas of abdominal subcutaneous fat (p=0.003). We observed no significant associations between these UCP1 genetic polymorphisms and thigh fat areas, visceral fat areas, or blood biochemical profiles, suggesting that this polymorphism might differentially affect fat accumulation in different parts of the human body, even though further study is needed to elucidate the mechanism of it.

Asunto(s)

Grasa Abdominal/diagnóstico por imagen , Canales Iónicos/genética , Proteínas Mitocondriales/genética , Polimorfismo Genético , Adulto , Pueblo Asiatico/genética , Secuencia de Bases , Femenino , Genotipo , Humanos , Canales Iónicos/metabolismo , Proteínas Mitocondriales/metabolismo , Datos de Secuencia Molecular , Tomografía Computarizada por Rayos X , Proteína Desacopladora 1

RESUMEN

Recent studies have provided some clues with regard to the relationship existing between uncoupling protein 1 (UCP1) and blood pressure in animal experiments. In an attempt to determine the genetic polymorphisms that are associated with blood pressure in humans, we have analyzed genetic polymorphisms in UCP1 gene. In this study, we assessed the association between UCP1 genotypes and systolic blood pressure (SBP) and diastolic blood pressure (DBP), in a population comprised of 832 Korean female subjects, using a general linear model, which was adjusted for age and body mass index (BMI). Among 4 genetic polymorphisms and the haplotypes constructed from them, haplotype3 of UCP1, UCP1-ht3[GAGA], evidenced significant associations with SBP (p=0.005) and DBP (p=0.013). However, this haplotype was not significantly associated with obesity phenotypes, including BMI or fat mass (p>0.05), thereby suggesting that its association with blood pressure was independent of obesity phenotypes.

Asunto(s)

Canales Iónicos/genética , Proteínas Mitocondriales/genética , Polimorfismo Genético , Adulto , Alelos , Presión Sanguínea , Índice de Masa Corporal , Femenino , Genotipo , Haplotipos , Humanos , Corea (Geográfico) , Modelos Genéticos , Obesidad/genética , Fenotipo , Proteína Desacopladora 1

RESUMEN

The purpose of this study is to estimate the effects of Ala55Val genetic polymorphism of uncoupling protein 2 on computed tomography-measured body fat area and calorie restriction-induced changes. Among 386 Korean female subjects, the AlaAla type was seen in 30.3%, the AlaVal type was seen in 47.2%, and the ValVal type was seen in 22.5%. This finding was in agreement with Hardy-Weinberg equilibrium. The frequency of the major Ala allele was 0.54, and that of the minor Val allele was 0.46, which were similar to those seen in Caucasian populations. When cross-sectional areas of fat tissues in the subjects were measured by computed tomography, it was shown that the total abdominal fat area and abdominal subcutaneous fat area were significantly smaller in the ValVal type compared with the AlaVal or AlaAla type (p=0.043 and p=0.044, respectively). The Ala55Val polymorphism had no effects on visceral fat area and thigh subcutaneous fat area. Among the 386 subjects, 236 subjects finished the 1-month calorie restriction program. The results showed that the body fat was reduced significantly less in the ValVal type compared with the other types (p=0.016), whereas the changes in lean body mass, protein, mineral, and water contents were not significantly different according to the Ala55Val polymorphism.

Asunto(s)

Tejido Adiposo , Dieta Reductora , Canales Iónicos/genética , Proteínas Mitocondriales/genética , Polimorfismo Genético/fisiología , Pérdida de Peso/genética , Grasa Abdominal , Composición Corporal/genética , Ingestión de Energía , Femenino , Humanos , Corea (Geográfico) , Grasa Subcutánea , Tomografía Computarizada por Rayos X , Proteína Desacopladora 2

RESUMEN

With the emerging role of hematopoietic stem cells as potential gene and cell therapy vehicles, there is an increasing need for safe and effective nonviral gene delivery systems. Here, we report that gene transfer and transfection efficiency in human hematopoietic and cord blood CD34+ cells can be enhanced by the use of low molecular weight polyethylenimine (PEI). PEIs of various molecular weights (800-750,000) were tested, and our results showed that the uptake of plasmid DNA by hematopoietic TF-1 cells depended on the molecular weights and the N/P ratios. Treatment with PEI 2K (m.w. 2000) at an N/P ratio of 80/1 was most effective, increasing the uptake of plasmid DNA in TF-1 cells by 23-fold relative to Lipofectamine 2000. PEI 2K-enhanced transfection was similarly observed in hematopoietic K562, murine Sca-1+, and human cord blood CD34+ cells. Notably, in human CD34+ cells, a model gene transferred with PEI 2K showed 21,043- and 513-fold higher mRNA expression levels relative to the same construct transfected without PEI or with PEI 25 K, respectively. Moreover, PEI 2K-treated TF-1 and human CD34+ cells retained good viability. Collectively, these results indicate that PEI 2K at the optimal N/P ratio might be used to safely enhance gene delivery and transfection of hematopoietic and human CD34+ stem cells.

Asunto(s)

Antígenos CD34/sangre , Células Madre Hematopoyéticas/fisiología , Polietileneimina/química , Transfección/métodos , Supervivencia Celular , ADN/administración & dosificación , Sangre Fetal/inmunología , Humanos , Interleucina-2/biosíntesis , Interleucina-2/genética , Células K562 , Peso Molecular , Plásmidos/genética , Polietileneimina/administración & dosificación , Polietileneimina/toxicidad

RESUMEN

Sp1 activates the transcription of many cellular and viral genes with the GC-box in either the proximal promoter or the enhancer. Sp1 is composed of several functional domains, such as the inhibitory domain (ID), two serine/threonine-rich domains, two glutamine-rich domains, three C2H2-type zinc finger DNA binding domains (ZFDBD), and a C-terminal D domain. The ZDDBD is the most highly conserved domain among the Sp-family transcription factors and plays a critical role in GC-box recognition. In this study, we investigated the protein-protein interactions occurring at the Sp1ZFDBD and the Sp1ID, and the molecular mechanisms controlling the interaction. Our results found that Sp1ZFDBD and Sp1ID repressed transcription once they were targeted to the proximal promoter of the pGal4 UAS reporter fusion gene system, suggesting molecular interaction with the repressor molecules. Indeed, mammalian two-hybrid assays, GST fusion protein pull-down assays, and co-immunoprecipitation assays showed that Sp1ZFDBD and Sp1ID are able to interact with corepressor proteins such as SMRT, NcoR, and BCoR. The molecular interactions appear to be regulated by MAP kinase/Erk kinase kinase (MEK). The molecular interactions between Sp1ID and the corepressor might explain the role of Sp1 as a repressor under certain circumstances. The siRNA-induced degradation of the corepressors resulted in an up-regulation of Sp1-dependent transcription. The cellular context of the corepressors and the regulation of molecular interaction between corepressors and Sp1ZFDBD or Sp1ID might be important in controlling Sp1 activity.

Asunto(s)

ADN/química , Quinasas Quinasa Quinasa PAM/metabolismo , Factor de Transcripción Sp1/fisiología , Transcripción Genética , Activación Transcripcional , Animales , Proteínas de Ciclo Celular/metabolismo , Línea Celular , Inmunoprecipitación de Cromatina , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Drosophila , Genes Reporteros , Glutatión Transferasa/metabolismo , Células HeLa , Humanos , Inmunoprecipitación , Luciferasas/metabolismo , Sistema de Señalización de MAP Quinasas , Modelos Biológicos , Mutagénesis Sitio-Dirigida , Mutación , Plásmidos/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismo , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes/química , Transducción de Señal , Factor de Transcripción Sp1/metabolismo , Transfección , Técnicas del Sistema de Dos Híbridos , Dedos de Zinc

RESUMEN

Although prolonged transgene expression in progenitor cells might be desirable for modified cell therapy, the viral promoter-based expression vector tends to promote transgene expression only for a limited period. Here, we examined the ability of cellular promoters from elongation factor-1alpha (EF-1alpha) and ubiquitin C to drive gene expression in hematopoietic TF-1 and mesenchymal progenitor cells. We compared the expression levels and duration of a model gene, interleukin-2, generated by the cellular promoters to those by the cytomegalovirus (CMV) promoter. The EF-1alpha and ubiquitin C promoters drove prolonged gene expression in hematopoietic TF-1 and mesenchymal progenitor cells, whereas the CMV promoter did not. At day 7 after transfection in TF-1 cells, the mRNA expression levels of interleukin-2 driven by the EF-1alpha and ubiquitin C promoters were 118- and 56-fold higher, respectively, than those driven by the CMV promoter. Similarly, in mesenchymal progenitor cells, the expression levels of interleukin-2 driven by the EF-1alpha and ubiquitin C promoters were 98- and 20-fold higher, respectively, than that driven by the CMV promoter-encoding plasmid. Moreover, the ubiquitin C promoter directed higher levels of green fluorescence protein expression in mesenchymal progenitor cells than did the CMV promoter. These results indicate that the use of cellular promoters such as those for EF-1alpha and ubiquitin C might direct prolonged gene expression in hematopoietic and mesenchymal progenitor cells.

Asunto(s)

Regulación del Desarrollo de la Expresión Génica/fisiología , Regulación de la Expresión Génica/fisiología , Mejoramiento Genético/métodos , Células Madre Hematopoyéticas/fisiología , Células Madre Mesenquimatosas/fisiología , Factor 1 de Elongación Peptídica/fisiología , Plásmidos/genética , Regiones Promotoras Genéticas/genética , Ingeniería de Proteínas/métodos , Ubiquitina C/fisiología , Diferenciación Celular/genética , Línea Celular , Células Madre Hematopoyéticas/citología , Humanos , Células Madre Mesenquimatosas/citología

RESUMEN

The xeroderma pigmentosum complementation group F (XPF) protein is a structure-specific endonuclease in a complex with ERCC1 and is essential for nucleotide excision repair (NER). We report a single cDNA of Caenorhabditis elegans (C. elegans) encoding highly similar protein to human XPF and other XPF members. We propose to name the corresponding C. elegans gene xpf. Messenger RNA for C. elegans xpf is 5'-tagged with a SL2 splice leader, suggesting an operon-like expression for xpf. Using RNAi, we showed that loss of C. elegans xpf function caused hypersensitivity to ultra-violet (UV) irradiation, as observed in enhanced germ cell apoptosis and increased embryonic lethality. This study suggests that C. elegans xpf is conserved in evolution and plays a role in the repair of UV-damaged DNA in C. elegans.

Asunto(s)

Proteínas de Caenorhabditis elegans/genética , Reparación del ADN , Proteínas de Unión al ADN/genética , Secuencia de Aminoácidos , Animales , Apoptosis , Evolución Biológica , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Daño del ADN/efectos de la radiación , ADN Complementario/genética , Pérdida del Embrión , Femenino , Genes Letales , Células Germinativas/fisiología , Humanos , Datos de Secuencia Molecular , Interferencia de ARN , Empalme del ARN , ARN Mensajero/genética , Homología de Secuencia de Aminoácido , Rayos Ultravioleta/efectos adversos

RESUMEN

To increase the potency of DNA vaccines, we constructed genetic fusion vaccines encoding antigen, secretion signal, and/or chemokine RANTES. The DNA vaccines encoding secreted hepatitis B surface antigen (HBsAg) were constructed by inserting HBsAg gene into an expression vector with an endoplasmic reticulum (ER)-targeting secretory signal sequence. The plasmid encoding secretory HBsAg (pER/HBs) was fused to cDNA of RANTES, generating pER/HBs/R. For comparison, HBsAg genes were cloned into pVAX1 vector with no signal sequence (pHBs), and further linked to the N-terminus of RANTES (pHBs/R). Immunofluorescence study showed the cytoplasmic localization of HBsAg protein expressed from pHBs and pHBs/R, but not from pER/HBs and pER/HBs/R at 48 h after transfection. In mice, RANTES-fused DNA vaccines more effectively elicited the levels of HBsAg-specific IgG antibodies than pHBs. All the DNA vaccines induced higher levels of IgG(2a) rather than IgG(1) antibodies. Of RANTES-fused vaccines, pER/HBs/R encoding the secreted fusion protein revealed much higher humoral and CD8(+) T cell-stimulating responses compared to pHBs/R. These results suggest that the immunogenicity of DNA vaccines could be enhanced by genetic fusion to a secretory signal peptide sequence and RANTES.

Asunto(s)

Quimiocina CCL5/inmunología , Antígenos de Superficie de la Hepatitis B/inmunología , Vacunas contra Hepatitis B/inmunología , Vacunas de ADN/inmunología , Animales , Fusión Artificial Génica/métodos , Linfocitos T CD8-positivos/inmunología , Células Cultivadas , Quimiocina CCL5/genética , Quimiocina CCL5/metabolismo , Retículo Endoplásmico/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente , Anticuerpos contra la Hepatitis B/sangre , Antígenos de Superficie de la Hepatitis B/genética , Antígenos de Superficie de la Hepatitis B/metabolismo , Vacunas contra Hepatitis B/administración & dosificación , Vacunas contra Hepatitis B/genética , Inmunización , Inmunoglobulina G/sangre , Ratones , Ratones Endogámicos BALB C , Músculos/citología , Señales de Clasificación de Proteína/genética , Proteínas Recombinantes de Fusión/inmunología , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética

RESUMEN

Complete thermodynamic binding profiles for the interaction of the anticancer drug, daunomycin with natural DNA and synthetic deoxypolynucleotides were described. Fluorescence titration method was used to estimate the equilibrium binding constants. Binding isotherms were found to be surprisingly complex in some cases, presumably because there were heterogeneous sites even in simple deoxypolynucleotides of repeating sequence. Some polynucleotides consisting of alternating sequence contain at least two different binding sites for daunomycin. The binding affinity of the primary binding sites of alternating and non-alternating sequences was found to differ by two orders of magnitude. An isothermal microtitration calorimeter was used to directly measure the binding enthalpy at 25 degrees C with a high sensitivity. The binding enthalpy of poly[d(A-T)] was found to be -5.5 Kcal/mol, which was much lower than any other polynucleotides, while the binding constant of the high affinity sites, was similar. In this report, the complete thermodynamic profiles of daunomycin binding to deoxypolynucleotides were reliably shown for the first time.

Asunto(s)

Antibióticos Antineoplásicos/metabolismo , ADN/metabolismo , Daunorrubicina/metabolismo , Polidesoxirribonucleótidos/metabolismo , Antibióticos Antineoplásicos/química , Composición de Base , Secuencia de Bases , Sitios de Unión , Calorimetría/métodos , ADN/química , Daunorrubicina/análogos & derivados , Daunorrubicina/química , Polidesoxirribonucleótidos/química , Secuencias Repetitivas de Ácidos Nucleicos , Espectrometría de Fluorescencia , Termodinámica , Volumetría/métodos

RESUMEN

The POZ domain is a protein-protein interaction motif that is found in many transcription factors, which are important for development, oncogenesis, apoptosis, and transcription repression. We cloned the POZ domain transcription factor, FBI-1, that recognizes the cis-element (bp -38 to -22) located just upstream of the core Sp1 binding sites (bp -22 to +22) of the ADH5/FDH minimal promoter (bp -38 to +61) in vitro and in vivo, as revealed by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. The ADH5/FDH minimal promoter is potently repressed by the FBI-1. Glutathione S-transferase fusion protein pull-down showed that the POZ domains of FBI-1, Plzf, and Bcl-6 directly interact with the zinc finger DNA binding domain of Sp1. DNase I footprinting assays showed that the interaction prevents binding of Sp1 to the GC boxes of the ADH5/FDH promoter. Gal4-POZ domain fusions targeted proximal to the GC boxes repress transcription of the Gal4 upstream activator sequence-Sp1-adenovirus major late promoter. Our data suggest that POZ domain represses transcription by interacting with Sp1 zinc fingers and by interfering with the DNA binding activity of Sp1.

Asunto(s)

Aldehído Oxidorreductasas/genética , Aldehído Oxidorreductasas/metabolismo , Proteínas de Unión al ADN/metabolismo , Factor de Transcripción Sp1/metabolismo , Factores de Transcripción , Transcripción Genética , Secuencia de Aminoácidos , Animales , Núcleo Celular/metabolismo , Cromatina/metabolismo , ADN/metabolismo , Desoxirribonucleasa I/metabolismo , Biblioteca de Genes , Células HeLa , Humanos , Ratones , Datos de Secuencia Molecular , Familia de Multigenes , Plásmidos/metabolismo , Reacción en Cadena de la Polimerasa , Pruebas de Precipitina , Regiones Promotoras Genéticas , Unión Proteica , Estructura Terciaria de Proteína , Homología de Secuencia de Aminoácido , Dedos de Zinc

RESUMEN

Telomeres are the ends of the linear chromosomes of eukaryotes and consist of tandem GT-rich repeats in telomere sequence i.e. 500-3000 repeats of 5'-TTAGGG-3' in human somatic cells, which are shortened gradually with age. The G-rich overhang of telomere sequence can adopt different intramolecular fold-backs and tetra-stranded DNA structures, in vitro, which inhibit telomerase activity. In this report, DNA binding agents to telomere sequence were studied novel therapeutic possibility to destabilize telomeric DNA sequences. Oligonucleotides containing the guanine repeats in human telomere sequence were synthesized and used for screening potential antitumor drugs. Telomeric DNA sequence was characterized using spectral measurements and CD spectroscopy. CD spectrum indicated that the double-stranded telomeric DNA is in a right-handed conformation. Polyacrylamide gel electrophoresis was performed for binding behaviors of antitumor compounds with telomeric DNA sequence. Drugs interacted with DNA sequence caused changes in the electrophoretic mobility and band intensity of the gels. Depending on the binding mode of the anticancer drugs, telomeric DNA sequence was differently recognized and the efficiency of cleavage of DNA varies in the bleomycin-treated samples under different conditions. DNA cleavage occurred at about 1% by the increments of 1 micromM bleomycin-Fe(III). These results imply that the stability of human telomere sequence is important in conjunction with the cancer treatment and aging process.

Asunto(s)

Antineoplásicos/metabolismo , ADN/metabolismo , Doxorrubicina/análogos & derivados , Secuencias Repetitivas de Ácidos Nucleicos , Telómero/genética , Bleomicina/metabolismo , Bleomicina/farmacología , Dicroismo Circular , ADN/química , ADN/efectos de los fármacos , Daño del ADN , Dactinomicina/metabolismo , Doxorrubicina/metabolismo , Humanos , Nogalamicina/metabolismo , Conformación de Ácido Nucleico , Telómero/efectos de los fármacos