Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Plant Dis ; 106(11): 2967-2973, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35306849

RESUMO

Rice false smut caused by the filamentous fungus Ustilaginoidea virens is a devastating grain disease in rice. Fungicides have been an important measure for the control of this disease. In this study, baseline sensitivities of 179 isolates of U. virens to the quinone outside inhibitor (QoI) fungicides azoxystrobin and pyraclostrobin were established. The distribution of the 50% effective concentration (EC50) values of each fungicide was unimodal. The frequency distribution of logarithmically transformed EC50 values fit or fit closer to a normal distribution. The ranges of EC50 values for azoxystrobin and pyraclostrobin were 0.001 to 0.864 and 0.001 to 0.569 µg/ml, with means and standard errors of the mean values of 0.203 ± 0.012 and 0.079 ± 0.006 µg/ml, respectively. There was a statistically significant and moderately positive correlation (n = 100, r = 0.469, P = 0.001) in sensitivity between these two fungicides. No cross-resistance was found between azoxystrobin, pyraclostrobin, and carbendazim or sterol demethylation inhibitor fungicides. Each fungicide had a significantly higher mean preventive efficacy compared with its curative efficacy. Field assays showed that the control efficacy of pyraclostrobin against rice false smut was greater than that of azoxystrobin. Pyraclostrobin had the best control of rice false smut in three rice varieties, with the control efficacy ranging from 81.5 to 95.5%, whereas azoxystrobin decreased the disease index by 64.1 to 69.2% under the same conditions. These results provide us a reference point in the management of U. virens and future QoI fungicide resistance monitoring programs.


Assuntos
Fungicidas Industriais , Oryza , Fungicidas Industriais/farmacologia , Oryza/microbiologia , Quinonas
2.
Phys Rev Lett ; 124(1): 010502, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31976724

RESUMO

Ensuring the nonentanglement-breaking (non-EB) property of quantum channels is crucial for the effective distribution and storage of quantum states. However, a practical method for direct and accurate certification of the non-EB feature is highly desirable. Here, we propose and verify a realistic source based measurement device independent certification of non-EB channels. Our method is resilient to repercussions on the certification from experimental conditions, such as multiphotons and imperfect state preparation, and can be implemented with an information incomplete set. We achieve good agreement between experimental outcomes and theoretical predictions, which is validated by the expected results of the ideal semiquantum signaling game, and accurately certify the non-EB channels. Furthermore, our approach is highly robust to effects from noise. Therefore, the proposed approach can be expected to play a significant role in the design and evaluation of realistic quantum channels.

3.
Phys Rev Lett ; 122(16): 160501, 2019 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-31075015

RESUMO

Measurement-device-independent quantum key distribution (MDI-QKD) can eliminate all detector side channels and it is practical with current technology. Previous implementations of MDI-QKD all used two symmetric channels with similar losses. However, the secret key rate is severely limited when different channels have different losses. Here we report the results of the first high-rate MDI-QKD experiment over asymmetric channels. By using the recent 7-intensity optimization approach, we demonstrate>10×higher key rate than the previous best-known protocols for MDI-QKD in the situation of large channel asymmetry, and extend the secure transmission distance by more than 20-50 km in standard telecom fiber. The results have moved MDI-QKD towards widespread applications in practical network settings, where the channel losses are asymmetric and user nodes could be dynamically added or deleted.

4.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1822-1828, 2019 May.
Artigo em Zh | MEDLINE | ID: mdl-31342708

RESUMO

The flower of Hibiscus syriacus has good ornamental and edible-medicinal values.In this study,four samples of two varieties,namely white multiple petals flower and pink multiple petals flower,were selected as test materials.And the optimum extraction conditions,relative molecular weight,monosaccharide composition and antioxidant activity of polysaccharides in flower were investigated.Through single factor experiment and response surface,the optimal extract conditions of polysaccharide were designed as follows:extraction temperature at 96.8℃,ratio of material to liquid of 43.5∶1 m L·g~(-1),extraction time of 3.1 h.Polysaccharides of H.syriacus flowers were analyzed by high performance gel chromatography.The average molecular masses of the 4 polysaccharide samples were1.49×10~5,1.25×10~5,1.01×10~5,1.37×10~5,respectively.Polysaccharides of H.syriacus flowers were mainly composed of glucose,mannose,galactose,rhamnose and arabinose by pre-column derivatization HPLC.The ratio of galactose was the highest in five monosaccharide,and the ratio of galactose to glucose was 1.656-4.496.In addition,crude polysaccharides of H.syriacus flowers showed potential antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)assay,total reducing capacity assay and ABTS assay in vitro,and its antioxidant effect showed a good dose-effect relationship with the concentration of crude polysaccharides.Among the tested varieties,polysaccharides of pink multiple petals flower and white multiple petals flower had the same molecular masses and monosaccharides composition,but the antioxidant activity of the polysaccharides of pink multiple petals flower was higher than that of the white flowers.The results of this study can provide a theoretical basis for the application of H.syriacus flower in the field of functional foods.


Assuntos
Antioxidantes/farmacologia , Hibiscus/química , Polissacarídeos/farmacologia , Antioxidantes/química , Flores/química , Monossacarídeos/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Pigmentação , Polissacarídeos/química
5.
Zhongguo Zhong Yao Za Zhi ; 43(10): 2025-2031, 2018 May.
Artigo em Zh | MEDLINE | ID: mdl-29933666

RESUMO

The study is aimed to fully analyze antioxidant activty and stability of color-related components from Dendrobium officinale flower. The contents of anthocyanins,carotenoids and flavonoids of 10 varieties including whole flower and labellum of D.officinale flower were detected using UV visible spectroscopy technique and evaluated for their 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·), superoxide anion radical (·O⁻2) and hydroxy radical (·OH) scavenging activty. And the effects of 4 kinds of metal ions (Cu²âº, Mg²âº, Al³âº,K⁺) and 2 kinds of food additives were investigated on the stability of anthocyanins pigment from D.officinale flower. The results indicated that the flower of D.officinale contained anthocyanins,carotenoids and flavonoids,and their contents in different parts of different families varied. The content of anthocyanins (1 330.9 µg·g⁻¹) in labellum was significantly higher than that in the whole flower (696.3 µg·g⁻¹). The content of carotenoids was positively correlated with the content of anthocyanins,and there was significant positive correlation between the scavenging capacities of the three free radicals and the contents of anthocyanin,respectively (0.415,0.384,0.455). The Cu²âº, Mg²âº, Al³âº, K⁺ and glucose showed significant color-enhancing effect and could increase the stability of anthocyanin in D.officinale flower,while ascorbic acids showed remarkably degradation effect of anthocyanin in D.officinale flower.


Assuntos
Antioxidantes/análise , Dendrobium/química , Flores/química , Antocianinas/análise , Carotenoides/análise , Flavonoides/análise , Compostos Fitoquímicos/análise
6.
Anal Bioanal Chem ; 409(23): 5547-5554, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28717898

RESUMO

The thiophene-modified rhodamine 6G (GYJ) has been synthesized as a novel chemosensor. The sensor has sufficiently high selectivity and sensitivity for the detection of Fe3+ and Al3+ ions (M3+) by fluorescence and ultraviolet spectroscopy with a strong ability for anti-interference performance. The binding ratio of M3+-GYJ complex was determined to be 2:1 according to the Job's plot. The binding constants for Fe3+ and Al3+ were calculated to be 3.91 × 108 and 5.26 × 108 M-2, respectively. All these unique features made it particularly favorable for cellular imaging applications. The obvious fluorescence microscopy experiments demonstrated that the probes could contribute to the detection of Fe3+ and Al3+ in related cells and biological organs with satisfying resolution. Graphical abstract GYJ has high selectivity and sensitivity for the detection of Fe(III) and Al(III) with the binding ratio of 2:1.


Assuntos
Alumínio/análise , Compostos Férricos/análise , Corantes Fluorescentes/química , Rodaminas/química , Tiofenos/química , Limite de Detecção , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
7.
Zhongguo Zhong Yao Za Zhi ; 42(20): 3919-3925, 2017 Oct.
Artigo em Zh | MEDLINE | ID: mdl-29243428

RESUMO

In order to provide new information on polysaccharide in Dendrobium officinale flowers,the monosaccharide composition and relative molecular mass distribution of 11 families of flowers were investigated and analyzed by high performance gel filtration chromatography (HPGFC) and pre-column derivatization ultra performance liquid chromatography (UPLC) in this study. Then cluster analysis was carried out for the monosaccharide peak areas by utilizing SPSS 19.0 software. The results showed that the polysaccharides of all the above 11 hybrid families of D. officinale flower were separated into three fractions (DOP-1, DOP-2 and DOP-3) with the average relative molecular mass of 5.53×105, 3.49×105 and 2.12×105. The polysaccharides in 11 different families were mainly composed of glucose, mannose, galactose, galacturonic acid and arabinose; mannose had the highest proportion among them, with mannose/glucose ratio of 0.302-3.335. Additionally, the relative contents of various monosaccharides in different families varied. 11 families of D. officinale flower could be classified into four categories according to their monosaccharide components and relative contents. In this study, the relative molecular mass distribution and monosaccharide composition of polysaccharides in D. officinale flowers were defined, which can provide foundations for its resource utilization..


Assuntos
Dendrobium/química , Flores/química , Monossacarídeos/química , Polissacarídeos/química , Manose
8.
Adv Mater ; 35(27): e2110068, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35853841

RESUMO

The advent of intense ultrashort optical pulses spanning a frequency range from terahertz to the visible has opened a new era in the experimental investigation and manipulation of quantum materials. The generation of strong optical field in an ultrashort time scale enables the steering of quantum materials nonadiabatically, inducing novel phenomenon or creating new phases which may not have an equilibrium counterpart. Ultrafast time-resolved optical techniques have provided rich information and played an important role in characterization of the nonequilibrium and nonlinear properties of solid systems. Here, some of the recent progress of ultrafast optical techniques and their applications to the detection and manipulation of physical properties in selected quantum materials are reviewed. Specifically, the new development in the detection of the Higgs mode and photoinduced nonequilibrium response in the study of superconductors by time-resolved terahertz spectroscopy are discussed.

9.
Zhongguo Yi Liao Qi Xie Za Zhi ; 30(3): 184-7, 223, 2006 May.
Artigo em Zh | MEDLINE | ID: mdl-16929775

RESUMO

The portable gastrointestinal wireless endoscope image receiver is developed and based on TMS320C6211 DSP. It can receive and demodulate the modulated signal which is transmitted from the camera-capsule, and then output the video signal. The synchronizing signals offered by SAA7114H are made best of and are used to design the time logic circuit. The fitful video signal can be collected under the control of the time logic circuit. The circuit can automatically get rid of useless blank data and only collect effective and good-quality video signals, and storage them in CF card. In addition, the image signal can be processed and compressed by DSP, and thus the data storage space and the data- analyzing time can be saved.


Assuntos
Endoscopia por Cápsula/métodos , Endoscópios Gastrointestinais , Interpretação de Imagem Assistida por Computador/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Cápsulas Endoscópicas , Sistemas Computacionais , Desenho de Equipamento , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Software
10.
Zhongguo Yi Liao Qi Xie Za Zhi ; 29(5): 328-30, 2005 Jul.
Artigo em Zh | MEDLINE | ID: mdl-16419934

RESUMO

The swallowable camera-capsule,described in the aper, 11 mm in diameter and 30 mm in length , contains a CMOS image sensor, an optical system, a battery, a light source, a transmitter, a antenna and so on. The CMOS image sensor and its driving circuit can be miniaturized with MEMS technology. Image signal can be transmitted by analog or digital way. Image signal can be wirelessly transmitted through serial data interface. Finally, the processing technics of the capsule's crust is introduced.


Assuntos
Cápsulas Endoscópicas , Tecnologia sem Fio , Desenho de Equipamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA