Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 18(5): e0285150, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37172062

RESUMO

Oaks (Quercus spp.) are widespread hardwood trees in the Northern Hemisphere and of high ecological, economic, and social values. Optimal experimental design of genetic trials is essential for accurate estimates of genetic parameters and improving the genetic merit of breeding stock. Here, we evaluate the use of post hoc row-column factors combined with spatial adjustment to improve genetic analyses of parents and individual trees in field progeny tests of plantation hardwoods, using cherrybark oak (Quercus pagoda Raf.) as an example. For tree height, post hoc incomplete blocking reduced ~14% more of the within-block environmental variance compared to the randomized complete block design (RCBD) model. Incomplete blocking also improved the heritability estimates for height by 7% to 14% compared to the original RCBD model. No clinal trend for growth breeding values was identified due to provenances. Our approach warrants the initial selection for height as early as age ~10 based on its moderate narrow-sense heritability of 0.2; however, diameter and volume need longer evaluation times. The post hoc incomplete blocking is more efficient and promising to improve the genetic analysis of Q. pagoda to minimize the environmental heterogeneity influences. Adjusting competition and spatial effects, including the distance principal components and autoregressive residual structure notably improves the model fit based on the observed reductions in AICs and BICs. Employing our approach is promising for hardwood genetic improvement in the southern USA.


Assuntos
Quercus , Quercus/genética , Projetos de Pesquisa , Melhoramento Vegetal , Árvores
2.
Sci Rep ; 11(1): 19072, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34561508

RESUMO

This study developed somatic embryogenesis protocols for Picea pungens (Engelm), an important ornamental species, including initiation, proliferation, maturation, germination, and acclimation. Somatic embryogenic tissues were induced from mature zygotic embryos of five families, with a frequency of [Formula: see text] 22% for each. Embryogenic tissues (ET) from 13 clones of three families were proliferated for one week, achieving an average rate of 179.1%. The ET of 38 clones of three families were cultured in maturation medium for six weeks; 188 mature embryos on average were counted per gram ET cultured, of which [Formula: see text] 81.1% appeared normal, and each clone developed at least 28 normally matured embryos. A total of 69.9% or more of cotyledonary somatic embryos germinated normally and developed into normal emblings. The experiment of transplanting the emblings into a greenhouse had an average survival rate of 68.5%. Considerable variation among and within families during initiation and proliferation was observed, but this variation decreased in the maturation and germination. Changing the concentration of plant growth regulator of the initiation medium did not significantly change the initiation frequency. We recommend incorporating these protocols into the current Picea pungens practical programs, although further research is essential to increase efficiencies and reduce cost.


Assuntos
Picea/embriologia , Sementes/crescimento & desenvolvimento , Germinação , Picea/fisiologia
3.
J Fluoresc ; 31(1): 1-9, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33057853

RESUMO

Functionalized carbon nitride quantum dots (CNQDs) are fabricated by moderate carbonization of L-tartaric acid and urea in oil acid media by a facile microwave-assisted solvothermal method. The obtained CNQDs are monodispersed with a narrow size distribution (average size of 3.5 nm), and exhibit excellent selectivity and sensitivity of fluorescence quenching for 2,4,6-trinitrophenol (TNP) with a quenching efficiency coefficient Ksv of 4.75 × 104 M-1. This sensing system exhibits a fast response time within 1 min and a wide linear response range from 0.1 to 15 µM. The limit of detection is as low as 87 nM, which is comparable or lower than the other probes. The application of the developed probe to the detection of TNP in spiked water samples yields satisfactory results. The mechanism of fluorescence quenching is also discussed. Graphical Abstract An optical sensor based on functionalized carbon nitride quantum dots (CNQDs) were fabricated from L-tartaric acid and urea by a facile one-pot microwave-assisted solvothermal method, and were effectively utilized to the detection of 2,4,6-trinitrophenol (TNP) based on fluorescence (FL) quenching.


Assuntos
Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Micro-Ondas , Nitrilas/química , Nitrilas/síntese química , Picratos/análise , Pontos Quânticos/química , Limite de Detecção , Picratos/química , Espectrometria de Fluorescência
4.
Sensors (Basel) ; 20(1)2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31878327

RESUMO

Accurately measuring tree diameter at breast height (DBH) and estimating tree positions in a sample plot are important in tree mensuration. The main aims of this paper include (1) developing a new, integrated device that can identify trees using the quick response (QR) code technique to record tree identifications, measure DBH, and estimate tree positions concurrently; (2) designing an innovative algorithm to measure DBH using only two angle sensors, which is simple and can reduce the impact of eccentric stems on DBH measures; and (3) designing an algorithm to estimate the position of the tree by combining ultra-wide band (UWB) technology and altitude sensors, which is based on the received signal strength indication (RSSI) algorithm and quadrilateral localization algorithm. This novel device was applied to measure ten 10 × 10 m square plots of diversified environments and various tree species to test its accuracy. Before measuring a plot, a coded sticker was fixed at a height of 1.3 m on each individual tree stem, and four UWB module anchors were set up at the four corners of the plot. All individual trees' DBHs and positions within the plot were then measured. Tree DBH, measured using a tree caliper, and the values of tree positions, measured using tape, angle ruler, and inclinometer, were used as the respective reference values for comparison. Across the plots, the decode rate of QR codes was 100%, with an average response time less than two seconds. The DBH values had a bias of 1.89 mm (1.88% in relative terms) and a root mean square error (RMSE) of 5.38 mm (4.53% in relative terms). The tree positions were accurately estimated; the biases on the x-axis and the y-axis of the tree position were -8.55-14.88 cm and -12.07-24.49 cm, respectively, and the corresponding RMSEs were 12.94-33.96 cm and 17.78-28.43 cm. The average error between the estimated and reference distances was 30.06 cm, with a standard deviation of 13.53 cm. The device is cheap and friendly to use in addition to its high accuracy. Although further studies are needed, our method provides a great alternative to conventional tools for improving the efficiency and accuracy of tree mensuration.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 215: 218-224, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30826580

RESUMO

Iron-doped carbon nitride nanoparticles (Fe-CNNPs) were prepared from citric acid, urea and ferric chloride through a convenient one-pot solvothermal method. Oleic acid was used as the reaction medium. The morphology and chemical composition of the obtained Fe-CNNPs were characterized by multiple methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). It is interesting to find that the Fe-CNNPs showed higher catalytic activity than horseradish peroxidase (HRP), and tetramethylbenzidine (TMB) can be catalytically oxidized in the presence of H2O2 to produce a color change in aqueous solution. As H2O2 can be generated in the oxidation process of glucose catalyzed by glucose oxidase (GOD), a novel sensitive method for the detection of glucose with a limit of detection (LOD) of 0.29 µM has been developed combined with the catalytic properties of GOD and Fe-CNNPs. The Fe-CNNPs with peroxidase mimetics activity may have potential applications in biotechnology field.


Assuntos
Glucose Oxidase/metabolismo , Glucose/análise , Peróxido de Hidrogênio/análise , Nanopartículas/química , Nitrilas/química , Colorimetria/métodos , Limite de Detecção , Modelos Lineares , Oxirredução
6.
Sci Rep ; 8(1): 8006, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29789595

RESUMO

Giant salvinia (Salvinia molesta) is one of the most noxious invasive species in the world. The fern is known to have primary, secondary, and tertiary growth forms, which are also commonly hypothesized as growth stages. The identification of these forms is primarily based on the size and folding status of the floating leaves. However, we identified 12 forms in the greenhouse and the field. Our experiments showed that the folding of floating leaves is a reversible trait dependent on water access. The floating leaves quickly fold in response to water shortage, reducing water loss and needs, decreasing growth, and avoiding trichome damage. The leaves re-open to allow trichomes repel water and enhance growth when having adequate water supply. Larger secondary or tertiary forms do not produce small-leaf primary forms without high intensity stress. These results do not support the hypothesis that three growth forms represent sequential growth stages. The abnormal small-leaf forms are the result of endocide-induced autotoxicity and some of them never grow into other forms. The development of abnormal forms and reversible leaf folding strategy in response to high stress along with rapid asexual reproduction are major adaptive traits contributing to the invasiveness of S. molesta.


Assuntos
Endotoxinas/farmacologia , Espécies Introduzidas , Traqueófitas/efeitos dos fármacos , Traqueófitas/crescimento & desenvolvimento , Biomassa , Ecossistema , Endotoxinas/metabolismo , Gleiquênias , Compostos Fitoquímicos/metabolismo , Compostos Fitoquímicos/farmacologia , Desenvolvimento Vegetal/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Traqueófitas/classificação , Traqueófitas/metabolismo , Água
7.
J Colloid Interface Sci ; 506: 373-378, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28750239

RESUMO

The application of fluorescent nanoparticles to the detection of inorganic ions and organic compounds has been attracted wide attention recently. In this paper, an "off-on" method for highly sensitive and selective detection of Hg2+ and l-cysteine (l-Cys) or Hg2+ and I- using home-made nitrogen-doped carbon quantum dots (N-CQDs) as fluorescent probe was reported. The N-CQDs with a fluorescence quantum yield of 42.2% were prepared using tartaric acid, citric acid and ethanediamine as the precursors in the oleic acid media. The fluorescence of the obtained N-CQDs could be quenched selectively and sensitively by the addition of Hg2+ (turn-off) with a detection limit of 83.5nM. When l-Cys or I- was added into the N-CQDs-Hg2+ system, the fluorescence was recovered effectively (turn-on). This process could be used to the detection of l-Cys or I- with a detection limit of 45.8 and 92.3nM, respectively.

8.
Oncol Rep ; 27(6): 1815-22, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22407148

RESUMO

Multiple myeloma (MM) is a clonal B-cell malignancy charactered by the aberrant proliferation of malignant plasma cells in the bone marrow. MM is still an incurable malignancy. In this regard, novel treatments are urgently required. MUC1 (mucin 1), a type І transmembrane protein, is overexpressed and aberrantly glycosylated in many carcinomas particularly in MM resulting in an antigenically distinct molecule and may be a potential target for specific immunotherapy. In this study, we first designed a unique DNA vaccine, termed MUC1-2-VNTR (various number tandem repeats) to investigate whether the vaccine could specifically suppress tumor growth in a murine multiple myloma model. Our results showed that the constructed DNA vaccine pcDNA3.1-VNTR elicited both humoral and cellular tumor-specific immune responses in the MM mouse model leading to delay in tumor growth and prolonged survival of the mice. Consequently, our study indicates that this DNA vaccine shows promise to be used as a novel strategy for the treatment of MM.


Assuntos
Vacinas Anticâncer/uso terapêutico , Repetições Minissatélites , Mucina-1/genética , Mieloma Múltiplo/terapia , Vacinas de DNA/uso terapêutico , Animais , Células COS , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Chlorocebus aethiops , Modelos Animais de Doenças , Feminino , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos BALB C , Mucina-1/imunologia , Mieloma Múltiplo/imunologia , Vacinas de DNA/genética , Vacinas de DNA/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...