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1.
Opt Express ; 31(3): 4978-5001, 2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36785452

RESUMEN

In many high-temperature gas-phase nanoparticle synthesis processes, freshly nucleated particles are liquid and solidify during growth and cooling. This study presents an approach to determine the location of the liquid-to-solid phase transition and the volume fraction and number density of particles of both phases within a gas phase reactor. Spectrally-resolved line-of-sight attenuation (LOSA) measurements are applied to a silicon nanoparticle aerosol generated from monosilane in a microwave plasma reactor. A phantom-based analysis using particle number density, particle size, and temperature distribution from direct numerical simulation (DNS) of the reacting flow indicates that the contributions from the two particle phases can be decoupled under practical conditions, even with noisy data. The approach was applied to analyze spatially and spectrally resolved LOSA measurements from the hot gas flow downstream of the plasma zone where both solid and liquid silicon particles coexist. Extinction spectra were recorded along a line perpendicular to the flow direction by a spectrometer with an electron-multiplying charge-coupled device (EMCCD) camera, and two-dimensional projections were deconvolved to obtain radial extinction coefficient distributions of solid and liquid particles across the cross-section of the flow. Particle number densities of both particle phases were retrieved simultaneously based on the size-dependent extinction cross-sections of the nanoparticles. The particle-size distribution was determined via thermophoretic sampling at the same location with subsequent transmission electron microscopy (TEM) analysis. The particle temperature distribution was determined from the particle's thermal radiation based on line-of-sight emission (LOSE) measurements. The approach for phase-selective data analysis can be transferred to other materials aerosol systems as long as significant differences exist in extinction spectra for the related different particle classes.

2.
Theor Appl Genet ; 136(9): 190, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37584740

RESUMEN

KEY MESSAGE: This study identified a novel SNP and developed a highly efficient KASP marker for drought tolerance in wheat by genotyping NILs targeting a major QTL for drought tolerance using an SNP array and validation with commercial varieties. Common wheat (Triticum aestivum L.) is an important winter crop worldwide and a typical allopolyploid with a large and complex genome. With global warming, the environmental volatility and incidence of drought in wheat-producing areas will increase. Molecular markers for drought tolerance are urgently needed to enhance drought tolerance breeding. Here, we genotyped four near-isogenic line (NIL) pairs targeting a major QTL qDSI.4B.1 on wheat chromosome arm 4BS for drought tolerance using the 90K SNP Illumina iSelect array and discovered a single nucleotide polymorphism (SNP) (Excalibur_c100336_106) with consistent genotype-phenotype associations among all four NIL pairs and their parents. Then, we converted the SNP into a Kompetitive Allele-Specific PCR (KASP) marker, with an accuracy of 100% for the four NIL pairs and their parents and as high as 81.8% for the 44 tested wheat lines with known phenotypes collected from Australia and China. Two genes near this SNP were suggested as candidate genes for drought tolerance in wheat after checking the Chinese Spring reference genome annotation version 1.1. One gene, TraesCS4B02G085300, encodes an F-box protein reportedly related to the ABA network, a main pathway for drought tolerance, and another gene, TraesCS4B02G085400, encodes a calcineurin-like metallophos-phoesterase transmembrane protein, which participates in Ca2+-dependent phosphorylation regulatory system. Based on this work and previous research on pre-harvest sprouting, we established a quick and efficient general SQV-based approach for KASP marker development, integrating genotyping by SNP arrays (S) using NILs targeting major QTL for a specific trait (Q) and validating them with commercial varieties (V). The identified SNP and developed KASP marker could be applied to marker-assisted selection in drought breeding, and further study of the candidate genes may improve our understanding of drought tolerance in wheat.


Asunto(s)
Sitios de Carácter Cuantitativo , Triticum , Genotipo , Mapeo Cromosómico , Triticum/genética , Triticum/metabolismo , Alelos , Resistencia a la Sequía , Fitomejoramiento , Fenotipo , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple
3.
Genomics ; 114(2): 110268, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35065191

RESUMEN

A genome-wide association study (GWAS) was performed in six environments to identify major or consistent alleles responsible for wheat yield traits in Australia and North China where rainfed farming system is adopted. A panel of 228 spring wheat varieties were genotyped by double digest restriction-site associated DNA genotyping-by-sequencing. A total of 223 significant marker-trait association (MTAs) and 46 candidate genes for large- or consistent-effect MTAs were identified. The results were compared with previous studies based on a mini-review of 23 GWAS analyses on wheat yield. A phenomenon seldom reported in previous studies was that MTAs responsible for the trait tended to cluster together at certain chromosome segments, and many candidate genes were in the form of gene clusters. Although linkage disequilibrium (LD) might contribute to the co-segregation of the regions, it also suggested that marker-assisted selection (MAS) or transgenic method targeting a single gene might not be as effective as MAS targeting a larger genomic region where all the genes or gene clusters underlying play important roles.


Asunto(s)
Estudio de Asociación del Genoma Completo , Triticum , Marcadores Genéticos , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Desequilibrio de Ligamiento , Fenotipo , Polimorfismo de Nucleótido Simple , Triticum/genética
4.
Anal Chem ; 94(35): 12095-12102, 2022 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-36006461

RESUMEN

Lipid droplets (LDs), which are ubiquitous organelles existing in almost all eukaryotic cells, have attracted a lot of attention in the field of cell biology over the last decade. For the biological study of LDs via fluorescence imaging, the superior LD fluorescent probes with environmental polarity-sensitive character are highly desired and powerful but are very scarce. Herein, we have newly developed such a kind of fluorescent probe named LDs-Red which enables us to visualize LDs and to further reveal their polarity information. This fluorescent probe displays the advantages of intense red/near-infrared emission, high LD staining specificity, and good photostability; thus, it would be very useful for LD fluorescence imaging application. As a result, the three-dimensional confocal imaging to visualize spatial distribution of LDs and the multicolor confocal imaging to simultaneously observe LDs and other cellular organelles have been realized using this new LD fluorescent probe. Furthermore, the polarity-sensitive emission character of this probe enables us to quantitatively determine the LD polarity via spectral scan imaging. Consequently, the cancer cells (HepG2, HeLa, and Panc02) displaying lower polarity of LDs than the normal cells (L929, U251, and HT22) have been systematically demonstrated. In addition, this polarity-sensitive probe displaying shorter fluorescence wavelengths in cancer cells than in normal cells has an important and potential ability to distinguish them.


Asunto(s)
Colorantes Fluorescentes , Gotas Lipídicas , Células HeLa , Humanos , Imagen Óptica , Coloración y Etiquetado
5.
Environ Res ; 207: 112649, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-34979128

RESUMEN

Exploring an efficient acclimation strategy to obtain robust bioanodes is of practical significance for antibiotic wastewater treatment by bioelectrochemical systems (BESs). This study investigated the effects of two acclimation conditions on chloramphenicol (CAP)-degrading anode biofilm formation in microbial fuel cells (MFCs). The one was continuously added the extracellular polymeric substances (EPS) extracted from anaerobic sludge and increasing concentrations of CAP after the first start-up phase, while the other was added the EPS-1 (N-acyl-homoserine lactones, namely AHLs were extracted from the EPS) at the same conditions. The results demonstrated that AHLs in the sludge EPS played a crucial role for enhanced CAP-degrading anode biofilm formation in MFCs. The AHL-regulation could not only maintain stable voltage outputs but also significantly accelerate CAP removal in the EPS MFC. The maximum voltage of 653.83 mV and CAP removal rate of 1.21 ± 0.05 mg/L·h were attained from the EPS MFC at 30 mg/L of CAP, which were 0.84 and 1.57 times higher than those from the EPS-1 MFC, respectively. These improvements were largely caused by the thick and 3D structured biofilm, strong and homogeneous cell viability throughout the biofilm, and high protein/polysaccharide ratio along with more conductive contents in the biofilm EPS. Additionally, AHLs facilitated the formation of a biofilm with rich biodiversity and balanced bacterial proportions, leading to more beneficial mutualism among different functional bacteria. More bi-functional bacteria (for electricity generation and antibiotic resistance/degradation) were specifically enriched by AHLs as well. These findings provide quorum sensing theoretical knowledge and practical instruction for rapid antibiotic-degrading electrode biofilm acclimation in BESs.


Asunto(s)
Acil-Butirolactonas , Fuentes de Energía Bioeléctrica , Acil-Butirolactonas/metabolismo , Biopelículas , Cloranfenicol/metabolismo , Electrodos , Matriz Extracelular de Sustancias Poliméricas/metabolismo , Aguas del Alcantarillado/microbiología
6.
Sensors (Basel) ; 22(21)2022 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-36365904

RESUMEN

In this paper, the influence of the edge effect on the simultaneous reconstruction of axisymmetric flame temperature and soot volume fraction profiles by a single CCD camera was investigated in detail. The reconstruction accuracy of the flame temperature profile and soot volume fraction was insensitive to the measurement error of the coefficient matrix. When the signal to ratio (SNR) of the measurement system for both the radiation intensity and coefficient matrix was as low as 46 dB, the reconstruction accuracy for both temperature and soot volume fraction was acceptable and was more influenced by the radiation intensity measurement error. The reconstruction of the flame temperature and soot volume fraction was greatly influenced by the edge effect. When the flame edge with weak radiation signals was ignored during the reconstruction, the relative reconstruction error for the temperature and soot volume fraction increased from the flame center to the edge, and reached an unacceptable value at the reconstruction boundary, especially for the soot volume fraction. The flame image boundary could be chosen as the unified reconstruction boundary to reconstruct the two-dimensional distribution of the temperature and soot volume fraction with satisfactory accuracy. The low soot volume fraction could influence the reconstruction accuracy for both the temperature and soot concentration in non-sooting regions. Moreover, there was no obvious regularity between the reconstruction accuracy of the temperature and soot volume fraction and the extension of the reconstruction boundary.

7.
Nano Lett ; 21(23): 10054-10061, 2021 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-34809433

RESUMEN

For nanostructures in advanced electronic and plasmonic systems, a single-crystal structure with controlled orientation is essential. However, the fabrication of such devices has remained challenging, as current nanofabrication methods often suffer from either polycrystalline growth or the difficulty of integrating single crystals with substrates in desired orientations and locations to create functional devices. Here we report a thermomechanical method for the controlled growth of single-crystal nanowire arrays, which enables the simultaneous synthesis, alignment, and patterning of nanowires. Within such diffusion-based thermomechanical nanomolding (TMNM), the substrate material diffuses into nanosized cavities under an applied pressure gradient at a molding temperature of ∼0.4 times the material's melting temperature. Vertically grown face-centered cubic (fcc) nanowires with the [110] direction in an epitaxial relationship with the (110) substrate are demonstrated. The ability to control the crystal structure through the substrate takes TMNM a major step further, potentially allowing all fcc and body-centered cubic (bcc) materials to be integrated as single crystals into devices.


Asunto(s)
Nanoestructuras , Nanocables , Nanoestructuras/química , Nanotecnología/métodos , Nanocables/química , Temperatura
8.
J Sci Food Agric ; 102(14): 6273-6284, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35510347

RESUMEN

BACKGROUND: Protein-polysaccharide complexes have been widely used to stabilize high-internal-phase emulsion (HIPEs). However, it is still unknown whether soy protein isolate-dextran (SPI-Dex) complexes can stabilize HIPEs or what is the effect of Dex concentration on the HIPEs. Furthermore, the non-covalent interaction mechanism between SPI and Dex is also unclear. Therefore, we fabricated SPI-Dex complexes and used them to stabilize HIPEs-loaded quercetin and explore the interaction mechanism between SPI and Dex, as well as the effect of Dex concentration on the particle size, ζ-potential, microstructure, rheology, quercetin encapsulation efficiency, and gastrointestinal fate of the HIPEs. RESULTS: Spectral analysis (fourier transform infrared spectroscopy, ultraviolet spectroscopy, and fluorescence spectroscopy) results identified the formation of SPI-Dex complexes, and indicated that the addition of Dex changed the spatial structure of SPI, whereas thermodynamic analysis (ΔH > 0, ΔS > 0) showed that hydrophobic interactions were the main driving forces in the formation of SPI-Dex complexes. Compared with HIPEs stabilized by SPI, the SPI-Dex complex-stabilized HIPEs had smaller particles (3000.33 ± 201.22 nm), as well as higher ζ-potential (-21.73 ± 1.10 mV), apparent viscosities, modulus, and quercetin encapsulation efficiency (98.19 ± 0.14%). In addition, in vitro digestion revealed that SPI-Dex complex-stabilized HIPEs significantly reduced the release of free fatty acid and improved quercetin bioaccessibility. CONCLUSION: HIPEs stabilized by SPI-Dex complexes delayed the release of free fat acid and improved the bioaccessibility of quercetin, and may be help in designing delivery systems for bioactive substances with specific properties. © 2022 Society of Chemical Industry.


Asunto(s)
Quercetina , Proteínas de Soja , Dextranos , Emulsiones/química , Ácidos Grasos no Esterificados , Tamaño de la Partícula , Polisacáridos , Proteínas de Soja/química
9.
Anal Chem ; 93(44): 14784-14791, 2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34704744

RESUMEN

Lipid droplets (LDs) are spherical organelles that participate in numerous biological processes. In order to visualize LDs on the nanoscale, nanoscopy fluorescence imaging is considered as the most attractive technique but is substantially limited by the characteristics of fluorescent probes. Thus, the development of a superior fluorescent probe that is capable of nanoscopy fluorescence imaging has attracted enormous attention. Herein, a benzodithiophene-tetraoxide-based molecule Lipi-BDTO has been developed that can easily undergo the stimulated emission depletion (STED) process and displays high photostability. These two characteristics of fluorescent probes finely satisfy the requirements of STED nanoscopy imaging. Indeed, applying the probe for STED imaging achieves a high resolution of 65 nm, belonging to one of the leading results of LDs fluorescence imaging. Furthermore, the high photostability of this fluorescent probe enables it to monitor the dynamics of LDs by time-lapse STED imaging as well as to visualize the three-dimensional (3D) spatial distribution of LDs by 3D STED imaging. Notably, the resolution of the 3D STED image represents one of the best LDs fluorescence imaging results so far. Besides STED nanoscopy imaging, the superior utility of this fluorescent probe has been also demonstrated in two-color 3D confocal imaging and four-color confocal imaging.


Asunto(s)
Colorantes Fluorescentes , Gotas Lipídicas , Células HeLa , Humanos , Microscopía Fluorescente , Imagen Óptica
10.
Opt Express ; 29(6): 8387-8406, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33820287

RESUMEN

In this study, emission and extinction spectroscopy were combined to in situ measure temperature and volume fraction distributions of liquid germanium nanoparticle gas-phase synthesized in an argon/hydrogen/germane flow through a microwave plasma. Emission of the hot particles and extinction against a continuous background were recorded by a spectrometer in the 380-703 nm and 230-556 nm ranges, respectively, selected based on the specific optical properties of the material. Absorption coefficients were deconvoluted from line-of-sight attenuation (LOSA) measurements by a least-square algorithm and then used to determine the local volume fraction distribution. The temperature field was derived from the line-of-sight emission (LOSE) spectra with the prior knowledge of absorption coefficients. A multi-wavelength reconstruction model was developed for the determination of the spatially-resolved distribution of the measured quantities assuming a stationary axisymmetric flow. Advantages of the method include experimental simplicity, low cost, and adaptability to up-scaled reactor sizes.

11.
Environ Geochem Health ; 43(12): 5177-5194, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34115270

RESUMEN

The types of land used for farmland can greatly influence the source and accumulation risk of heavy metals in soil. However, the apportioning quantitatively the source of soil heavy metals has been studied insufficiently, especially in terms of different types of farmland. In this study, a total of 252 soil samples were taken from dry land, paddy fields and greenhouse fields in the Jinyuan district of Taiyuan city, China, to assess the accumulation risk of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn). The results were then integrated, and source apportionment was evaluated by geospatial analysis, multivariate statistical analysis and positive matrix factorization (PMF). Cr, Cd and Hg were the dominant pollutants in the studied area. Accumulation risk by Cd and Cu was more severe in greenhouse fields than in dry land or paddy fields, whereas As, Hg and Pb had relatively higher accumulation in paddy fields than in dry land or greenhouse fields. Hg was derived mainly from coal combustion by atmospheric precipitation for the three types of farmland. Long-term irrigation using sewage is the main reason for the accumulation of Cu and Ni in dry land soil, Cu and Zn in paddy field soil and Zn in greenhouse soil. Cd in dry land, Cd and Pb in paddy fields and Cd, Cu, Ni and Pb in greenhouse fields were primarily added to soil through fertilization. Sewage irrigation and fertilization were the dominant sources of heavy metals for paddy field (31.3%) and greenhouse field (33.1%), respectively.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Agricultura , China , Monitoreo del Ambiente , Granjas , Metales Pesados/análisis , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis
12.
Phys Rev Lett ; 124(3): 036102, 2020 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-32031828

RESUMEN

Large-scale, controlled fabrication of ordered phases is challenging at the nanoscale, yet highly demanded as their well-ordered structure and chemistry is the key for advanced functionality. Here, we demonstrate a general nanomolding process of ordered phases based on atomic diffusion. Resulting nanowires are single crystals and maintain their composition and structure throughout their length, which we explain by a self-ordering process originating from their narrow Gibbs free energy. The versatility, control, and precision of this thermomechanical nanomolding method of ordered phases provides new insights into single crystal growth and suggest itself as a technology to enable wide spread usage for nanoscale and quantum devices.

13.
Proc Natl Acad Sci U S A ; 114(28): 7266-7271, 2017 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-28655845

RESUMEN

From colony formation in bacteria to wound healing and embryonic development in multicellular organisms, groups of living cells must often move collectively. Although considerable study has probed the biophysical mechanisms of how eukaryotic cells generate forces during migration, little such study has been devoted to bacteria, in particular with regard to the question of how bacteria generate and coordinate forces during collective motion. This question is addressed here using traction force microscopy. We study two distinct motility mechanisms of Myxococcus xanthus, namely, twitching and gliding. For twitching, powered by type-IV pilus retraction, we find that individual cells exert local traction in small hotspots with forces on the order of 50 pN. Twitching bacterial groups also produce traction hotspots, but with forces around 100 pN that fluctuate rapidly on timescales of <1.5 min. Gliding, the second motility mechanism, is driven by lateral transport of substrate adhesions. When cells are isolated, gliding produces low average traction on the order of 1 Pa. However, traction is amplified approximately fivefold in groups. Advancing protrusions of gliding cells push, on average, in the direction of motion. Together, these results show that the forces generated during twitching and gliding have complementary characters, and both forces have higher values when cells are in groups.


Asunto(s)
Proteínas Bacterianas/metabolismo , Movimiento , Myxococcus xanthus/fisiología , Adhesión Bacteriana , Biopelículas , Fimbrias Bacterianas/fisiología , Microscopía , Modelos Biológicos , Movimiento (Física) , Presión , Estrés Mecánico , Factores de Tiempo
14.
BMC Plant Biol ; 19(1): 348, 2019 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-31399046

RESUMEN

BACKGROUND: Resistance to pre-harvest sprouting (PHS) is one of the major objectives in wheat breeding programs. However, the complex quantitative nature of this trait presents challenges when breeding for PHS resistance. Characterization of PHS using near-isogenic lines (NILs) targeting major quantitative trait locus/loci (QTL/QTLs) can be an effective strategy for the identification of responsible genes and underlying mechanisms. RESULTS: In this study, multiple pairs of NILs were developed and confirmed for a major QTL located on the 4BL chromosome arm that contributes to PHS resistance in wheat, using a combined heterogeneous inbred family method and a fast generation cycling system. Phenotypic characterization of these confirmed NILs revealed significant differences in PHS resistance between the isolines, where the presence of the resistant allele increased the resistance to sprouting on spikes by 54.0-81.9% (average 70.8%) and reduced seed germination by 59.4-70.5% (average 66.2%). The 90 K SNP genotyping assay on the confirmed NIL pairs identified eight SNPs on 4BL, associated with five candidate genes; two of the candidate genes were related to seed dormancy. Agronomic traits in the NIL pairs were investigated; both plant height and grain number per spike were positively correlated with PHS susceptibility. CONCLUSIONS: This study confirmed multiple pairs of NILs and identified SNPs between PHS isolines, which are valuable resources for further fine-mapping of this locus to clone the major genes for PHS resistance and investigate the possible functional regulation of these genes on important agronomic traits, such as plant height and grain number per spike.


Asunto(s)
Triticum/genética , Cromosomas de las Plantas , Genotipo , Fenotipo , Fitomejoramiento , Desarrollo de la Planta/genética , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Triticum/crecimiento & desarrollo , Triticum/metabolismo
15.
Phys Rev Lett ; 122(24): 248102, 2019 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-31322369

RESUMEN

Combining high-resolution single cell tracking experiments with numerical simulations, we show that starvation-induced fruiting body formation in Myxococcus xanthus is a phase separation driven by cells that tune their motility over time. The phase separation can be understood in terms of cell density and a dimensionless Péclet number that captures cell motility through speed and reversal frequency. Our work suggests that M. xanthus takes advantage of a self-driven nonequilibrium phase transition that can be controlled at the single cell level.


Asunto(s)
Myxococcus xanthus/fisiología , Movimiento Celular/fisiología , Myxococcus xanthus/química , Myxococcus xanthus/citología , Transición de Fase
16.
Ecotoxicol Environ Saf ; 173: 331-338, 2019 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-30784796

RESUMEN

Microplastics can have strong sorption capacity for many contaminants, thus greatly influencing the fate, transport and bioavailability of those contaminants in the environment. However, the effect of particle size on contaminant sorption by microplastics is still poorly understood. This study investigated the sorption of phenanthrene and nitrobenzene to micron-, submicron- and nano- sized polystyrene microplastics of 170 µm, 102 µm, 50 µm, 30 µm, 800 nm, 235 nm or 50 nm. All phenanthrene sorption isotherms and most nitrobenzene sorption isotherms were linear because of the strong sorption capacity of microplastics and the hydrophobic partitioning. The log Kd values ranged between 3.07-4.20 and 1.58-3.14 log (L/kg) for phenanthrene and nitrobenzene, respectively. The log Kd values of phenanthrene and nitrobenzene both increased with decreasing particle size for micron-sized polystyrenes (micro-polystyrene) and submicron-sized polystyrenes (submicro-polystyrene). However, in comparison with 235 nm submicro-polystyrene, the log Kd values of 50 nm nano-polystyrene were significantly lower for phenanthrene and comparable for nitrobenzene because its aggregation greatly reduced the effective surface area accessible for sorption. The results improved our understanding of the fate and risks of microplastics associated with the two typical organic contaminants in the micrometer to nanometer scale.


Asunto(s)
Nitrobencenos/química , Fenantrenos/química , Poliestirenos/química , Contaminantes Químicos del Agua/química , Adsorción
17.
Nucleic Acids Res ; 44(9): 4233-42, 2016 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-27098036

RESUMEN

The Sulfolobales host a unique family of crenarchaeal conjugative plasmids some of which undergo complex rearrangements intracellularly. Here we examined the conjugation cycle of pKEF9 in the recipient strain Sulfolobus islandicus REY15A. The plasmid conjugated and replicated rapidly generating high average copy numbers which led to strong growth retardation that was coincident with activation of CRISPR-Cas adaptation. Simultaneously, intracellular DNA was extensively degraded and this also occurred in a conjugated Δcas6 mutant lacking a CRISPR-Cas immune response. Furthermore, the integrated forms of pKEF9 in the donor Sulfolobus solfataricus P1 and recipient host were specifically corrupted by transposable orfB elements, indicative of a dual mechanism for inactivating free and integrated forms of the plasmid. In addition, the CRISPR locus of pKEF9 was progressively deleted when conjugated into the recipient strain. Factors influencing activation of CRISPR-Cas adaptation in the recipient strain are considered, including the first evidence for a possible priming effect in Sulfolobus The 3-Mbp genome sequence of the donor P1 strain is presented.


Asunto(s)
ADN de Archaea/genética , Sulfolobus solfataricus/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Evolución Molecular , Plásmidos/genética , Sulfolobus solfataricus/citología , Sulfolobus solfataricus/crecimiento & desarrollo
18.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 43(3): 229-239, 2018 Mar 28.
Artículo en Zh | MEDLINE | ID: mdl-29701183

RESUMEN

OBJECTIVE: To explore the effect of intervention of E-cadherin (E-cad) and B-lymphoma Moloney murine leukemia virus insertion region-1 (Bmi-1) mediated by transcription activator-like effector nuclease (TALEN) on the biological behaviors of nasopharyngeal carcinoma cells.
 Methods: Multi-locus gene targeting vectors pUC-DS1-CMV-E-cad-2A-Neo-DS2 and pUC-DS1-Bmi-1 shRNA-Zeo-DS2 were constructed, and the E-cad and Bmi-1 targeting vectors were transferred with TALEN plasmids to CNE-2 cells individually or simultaneously. The integration of target genes were detected by PCR, the expressions of E-cad and Bmi-1 were detected by Western blot. The changes of cell proliferation were detected by cell counting kit-8 (CCK-8) assay. The cell cycle and apoptosis were detected by flow cytometry. The cell migration and invasion were detected by Transwell assay.
 Results: The E-cad and Bmi-1 shRNA expression elements were successfully integrated into the genome of CNE-2 cells, the protein expression level of E-cad was up-regulated, and the protein expression level of Bmi-1 was down-regulated. The intervention of E-cad and Bmi-1 didn't affect the proliferation, cell cycle and apoptosis of CNE-2 cells, but it significantly inhibited the migration and invasion ability of CNE-2 cells. Furthermore, the intervention of E-cad and Bmi-1 together significantly inhibited the migration ability of nasopharyngeal carcinoma cells compared with the intervention of E-cad or Bmi-1 alone (all P<0.01).
 Conclusion: The joint intervention of E-cad and Bmi-1 mediated by TALEN can effectively inhibit the migration and invasion of nasopharyngeal carcinoma cells in vitro, which may lay the preliminary experimental basis for gene therapy of human cancer.


Asunto(s)
Apoptosis/fisiología , Cadherinas/fisiología , Carcinoma/patología , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Neoplasias Nasofaríngeas/patología , Complejo Represivo Polycomb 1/fisiología , Proteínas Proto-Oncogénicas/fisiología , Nucleasas de los Efectores Tipo Activadores de la Transcripción/metabolismo , Animales , Cadherinas/genética , Carcinoma/genética , Carcinoma/metabolismo , Ciclo Celular/fisiología , Línea Celular Tumoral , Vectores Genéticos , Humanos , Técnicas In Vitro , Ratones , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Complejo Represivo Polycomb 1/genética , Proteínas Proto-Oncogénicas/genética
19.
Appl Microbiol Biotechnol ; 101(20): 7435-7443, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28887634

RESUMEN

In recent years, a variety of genetic tools have been developed and applied to various filamentous fungi, which are widely applied in agriculture and the food industry. However, the low efficiency of gene targeting has for many years hampered studies on functional genomics in this important group of microorganisms. The emergence of CRISPR/Cas9 genome-editing technology has sparked a revolution in genetic research due to its high efficiency, versatility, and easy operation and opened the door for the discovery and exploitation of many new natural products. Although the application of the CRISPR/Cas9 system in filamentous fungi is still in its infancy compared to its common use in E. coli, yeasts, and mammals, the deep development of this system will certainly drive the exploitation of fungal diversity. In this review, we summarize the research progress on CRISPR/Cas9 systems in filamentous fungi and finally highlight further prospects in this area.


Asunto(s)
Sistemas CRISPR-Cas , Hongos/genética , Edición Génica/métodos , Genoma Fúngico , Microbiología Industrial/métodos , Agricultura/métodos , Industria de Alimentos/métodos
20.
Molecules ; 21(9)2016 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-27617994

RESUMEN

The search for new molecular constructs that resemble the critical two-metal binding pharmacophore and the halo-substituted phenyl functionality required for HIV-1 integrase (IN) inhibition represents a vibrant area of research within drug discovery. As reported herein, we have modified our recently disclosed 1-[2-(4-fluorophenyl)ethyl]-pyrrole-2,5-dione scaffolds to design 35 novel compounds with improved biological activities against HIV-1. These new compounds show single-digit micromolar antiviral potencies against HIV-1 and low toxicity. Among of them, compound 9g and 15i had potent anti-HIV-1 activities (EC50 < 5 µM) and excellent therapeutic index (TI, CC50/EC50 > 100). These two compounds have potential as lead compounds for further optimization into clinical anti-HIV-1 agents.


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH/tratamiento farmacológico , VIH-1/metabolismo , Pirazoles , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Fármacos Anti-VIH/farmacología , Línea Celular , Evaluación Preclínica de Medicamentos , Infecciones por VIH/metabolismo , Humanos , Pirazoles/síntesis química , Pirazoles/química , Pirazoles/farmacología
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