Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Hortic Res ; 10(2): uhac274, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37533674

RESUMO

This work demonstrated that melatonin increases continuously in seeds, particularly seed coats, during berry ripening. Exogenous melatonin treatments significantly increased the proanthocyanidin (PA) content, partially through ethylene signaling, in seed coats. VvMYB14 expression exhibited patterns similar to melatonin accumulation over time, which was largely induced by melatonin treatment in seed coats during berry ripening. Additionally, VvMYB14 bound to the MBS element of the VvMYBPA1 promoter to activate expression. VvMYB14 overexpression largely upregulated expression of VvMYBPA1, VvMYBPA2 and VvLAR1 and increased the PA content in grape seed-derived calli. Similar increases in AtTT2 and AtBAN expression and PA content were found in VvMYB14-overexpressing Arabidopsis seeds. It was also observed that VvMYB14 overexpression increased ethylene production and thereby induced expression of VvERF104, which bound to the ERF element of the VvMYBPA2 promoter and activated its expression. Additionally, VvERF104 suppression reduced the VvMYB14 overexpression-induced increases in expression of VvMYBPA2 and VvLAR1 and PA content. Further experiments revealed that melatonin-induced increases in the expression of VvMYBPA1, VvMYBPA2, VvERF104 and VvLAR1 and PA accumulation were significantly reduced in VvMYB14-suppressing grape calli and leaves. Collectively, VvMYB14 mediates melatonin-induced PA biosynthesis by directly transactivating VvMYBPA1 expression and indirectly upregulating VvMYBPA2 expression via VvERF104.

2.
ACS Omega ; 8(10): 9154-9169, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36936336

RESUMO

The lacustrine shale of the Middle Permian Lucaogou Formation in the Jimusar Sag is the principal prospective unconventional target in the Junggar Basin. The effect of petroleum generation and retention on nanopore structure change during thermal maturity in lacustrine shale is still unclear. In this study, two laminated and two massive shale samples from the Permian Lucaogou Formation were selected to study this change by closed hydrous pyrolysis. The pyrolysis temperatures were 295, 320, 345, 370, and 400 °C, which cover from the mature to the post-mature stage. Total organic carbon (TOC), Rock-Eval, and low-pressure N2 adsorption tests on pyrolyzed shale samples before and after extractable organic matter (EOM) extraction were conducted systematically. The results indicate that (1) the petroleum generation on nanopore structure change is in stages. The peak nanopore volume expanding stage is the late oil window (R o = 0.9-1.35%). At the post-mature stage (R o > 1.35%), the mesopore volume decreased and the majority of the nanopore space is from macropores. (2) The presence of EOM decreased both mesopores and macropores in the peak oil window. (3) The organic-rich laminated shale generated more macropores than massive shale with increasing thermal maturity. The results of this study shed light on the dynamic effect of laminae fabric, petroleum generation, and retention on shale nanopore structure change across the oil window.

3.
PLoS One ; 17(11): e0278119, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36441707

RESUMO

As the foundation of the industrial economy, the equipment manufacturing industry takes an important position on the China-EU trade. Based on the analysis of the overall trend and structure of China-EU equipment manufacturing industry trade in 2007-2020, this article involves the construction of trade concentration into trade dependence metrics, and then calculate the degree of interdependence between China and EU equipment manufacturing trade in 2020. The perspective of the intra-industry specialization will be used to analyze China-EU equipment manufacturing trade dependency in 2020. The results show that: (1) Although China-EU equipment manufacturing trade has continued to grow, China had an imbalanced export structure to the EU, and electronic equipment exports are too high; (2) Regardless of import or export, the trade dependence of the EU countries on China about equipment manufacturing was higher than that of China on European countries; (3) China mainly depended on the EU about the high-end equipment manufacturing trade, which brings risks to Chinese manufacturing supply chains.


Assuntos
Comércio , Indústrias , Indústria Manufatureira , Especialização , China
4.
Nat Commun ; 13(1): 1835, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35383187

RESUMO

Photothermoelectric materials have important applications in many fields. Here, we joined a silver nanostructure film and a carbon nanotube film by van der Waals force to form a heterojunction, which shows excellent photothermal and photoelectric conversion properties. The local temperature difference and the output photovoltage increase rapidly when the heterojunction is irradiated by lasers with wavelengths ranging from ultraviolet to terahertz. The maximum temperature difference reaches 215.9 K, which is significantly higher than that of other photothermoelectric materials reported in the literature. The photothermal and photoelectric responsivity depend on the wavelength of lasers, which are 175~601 K W-1 and 9.35~40.4 mV W-1, respectively. We demonstrate that light absorption of the carbon nanotube is enhanced by local surface plasmons, and the output photovoltage is dominated by Seebeck effect. The proposed heterostructure can be used as high-efficiency sensitive photothermal materials or as ultra-wideband fast-response photoelectric materials.

5.
Hortic Res ; 8(1): 43, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33642583

RESUMO

The interplay between melatonin and ethylene in the regulation of fruit metabolism and the underlying molecular mechanism of this interplay remain largely unclear. Here, widely targeted metabolomics analysis revealed a total of 464 metabolites present in berry skin. Among them, 27 significantly differentially accumulated metabolites (DAMs) were produced in response to melatonin treatment in the presence or absence of 1-MCP. Most of the DAMs were secondary metabolites, including flavonoids, phenolic acids, stilbenes, and flavonols. Additionally, the accumulation of 25 DAMs was regulated by melatonin via ethylene. RNA-seq analysis indicated that melatonin primarily regulated the pathways of plant hormone signal transduction and secondary metabolite biosynthesis via ethylene. Gene-metabolite association analysis showed that melatonin regulated the expression of the VvSTS1, VvF3H, VvLAR2, and VvDFR genes, suggesting that these genes may play key roles in regulating secondary metabolites in the skin; additionally, VvMYB14 and VvACS1 were suggested to be involved in the regulation of secondary metabolites. Further experiments revealed that melatonin induced the expression of VvMYB14 and that VvMYB14 increased ethylene production by transcriptionally activating VvACS1, thereby affecting the accumulation of secondary metabolites. Collectively, melatonin promotes ethylene biosynthesis and alters secondary metabolite accumulation through the regulation of VvACS1 by VvMYB14.

6.
RSC Adv ; 11(32): 19482-19491, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35479257

RESUMO

The ultraviolet to terahertz band forms the main focus of optoelectronics research, while light detection in different bands generally requires the use of different materials and processing methods. However, researchers are aiming to realize multi-band detection simultaneously in the same device in certain specific application scenarios and ultra-wideband photoelectric detectors can also realize multi-function and multi-system integration. Therefore, the research and development work on ultra-wideband photoelectric detectors has important practical application value. Here, we produced self-powered suspended Pd-reduced graphene oxide-Ti (Pd-rGO-Ti) photodetectors. We varied the properties of the rGO films by using different annealing temperatures and achieved p-doping and n-doping of the films by evaporating palladium films and titanium films, respectively, thus enabling preparation of photothermoelectric (PTE) photodetectors based on rGO films. The resulting detectors have excellent photoelectric responses over a wideband illumination wavelength range from 375 nm to 118.8 µm (2.52 THz). At the same time, we determined the best experimental conditions and device structure by varying the channel width, the laser spot irradiation position and the experimental atmospheric pressure. The maximum responsivity obtained from our detectors is 142.08 mV W-1, the response time is approximately 100-200 ms and the devices have high detection sensitivity. Based on this work, we assumed in the subsequent experiments that detectors with higher performance can be obtained by reducing the channel width and atmospheric pressure. With advantages that include simple fabrication, low cost, large-scale production potential and ultra-wideband responses, these Pd-rGO-Ti photodetectors have broad application prospects in high-performance integrated optoelectronics.

7.
ACS Appl Mater Interfaces ; 12(45): 50763-50771, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33136365

RESUMO

Graphene has excellent electrical, optical, thermal, and mechanical properties that make it an ideal optoelectronic material. However, it still has some problems, such as a very low light absorption rate, which means it cannot meet the application requirements of high-performance optoelectronic devices. Here, we produce a high-responsivity photodetector based on a monolayer graphene/RbAg4I5 composite nanostructure. With the aid of poly(methyl methacrylate), we suspend the monolayer graphene on a hollow carving groove with a width of 100 µm. A RbAg4I5 film evaporated on the back of the graphene causes the composite nanostructure to generate a large photocurrent under periodic illumination. Experimental results show that the dissociation and recombination of ion-electron bound states (IEBSs) are responsible for the excellent photoresponse. The device has very high (>1 A W-1) responsivity in wide-band illumination wavelength from 375 nm to 808 nm, especially at 375 nm, where it shows a responsivity of up to ∼5000 A W-1. We designed the dimensions of the carving groove to allow the light spot to cover the entire groove, and we cut the graphene sheet to match the length of the carving groove. With the structural optimizations, the energy of light can be used more efficiently to dissociate the IEBSs, which greatly improves the photoresponse of optoelectronic devices based on the proposed monolayer graphene/RbAg4I5 composite nanostructure.

8.
Nanotechnology ; 31(45): 455201, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-32717725

RESUMO

A macroscopic silver nanowire (AgNW) network is grown by solid state ionics method. The ion flow during growth of the AgNW network is controlled by maintaining a current in the order of 10-7 A. Scanning electron microscopy (SEM) analysis reveals that the growth direction of AgNWs in the network is irregular and spread evenly in all directions and the nanowires are 40-160 nm in diameter. The microcosmic mechanism of silver nanostructures grown by the solid state ionics method is established by real time and in situ SEM analysis of the growth process of the AgNW networks. To study the photoelectric properties of the network, a self-supported AgNW network sample (∼1 mm wide and 8 mm long) is irradiated with lasers of different wavelengths of 375, 405, 532, 633, 808, and 1064 nm and 10.6 µm, and changes in the current between the two ends of the sample are recorded. The network displays negative photoconductance effect, and the maximum light responsivity is 43 mA W-1. The network displays light responsivity in the ultraviolet light-to-mid-infrared light region, with response times of tens of milliseconds. These findings indicate that the AgNW network has broad application prospect in ultra-wide spectrum photoelectric detection.

9.
BMC Mol Cell Biol ; 21(1): 51, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620073

RESUMO

BACKGROUND: Methotrexate (MTX) is an antifolate agent which is widely used in clinic for treating malignancies, rheumatoid arthritis and ectopic pregnancy. As reported, MTX has side effects on gastrointestinal system, nervous system and reproductive system, while its potential damages on oocyte quality are still unclear. It is known that oocyte quality is essential for healthy conception and the forthcoming embryo development. Thus, this work studied the effects of MTX on the oocyte quality. RESULTS: We established MTX model mice by single treatment with 5 mg/Kg MTX. Both morphological and molecular biology studies were performed to assess the in-vivo matured oocytes quality and to analyze the related mechanisms. The in-vivo matured oocytes from MTX-treated mice had poor in-vitro fertilization ability, and the resulting embryo formation rates and blastocyst quality were lower than the control group. We found that the in-vivo matured MTX-treated mouse oocytes displayed abnormal transcript expressions for genes of key enzymes in the folate cycles. MTX increased the rate of abnormal chromosome alignment and affected the regulation of chromosome separation via disrupting the spindle morphology and reducing the mRNA expressions of MAD2 and Sgo1. MTX reduced the DNA methylation levels in the in-vivo matured oocytes, and further studies showed that MTX altered the expressions of DNMT1 and DNMT 3b, and may also affect the levels of the methyl donor and its metabolite. CONCLUSIONS: MTX impaired the in-vivo matured mouse oocyte quality by disturbing folate metabolism and affecting chromosome stability and methylation modification.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Metotrexato/efeitos adversos , Oócitos/patologia , Animais , Diferenciação Celular/genética , Cromossomos de Mamíferos/efeitos dos fármacos , Cromossomos de Mamíferos/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Desenvolvimento Embrionário/efeitos dos fármacos , Fertilização in vitro , Ácido Fólico/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Camundongos Endogâmicos ICR , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/metabolismo , Transcrição Gênica/efeitos dos fármacos
10.
BMC Plant Biol ; 20(1): 231, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32448301

RESUMO

BACKGROUND: Melatonin can regulate plant growth, development and biotic responses by causing global changes in gene expression; however, the melatonin-induced changes in gene expression via the modification of DNA methylation remain unclear in plants. RESULTS: A total of 1,169,852 and 1,008,894 methylated cytosines (mCs) were identified in the control and melatonin-treated grape berries, respectively, and mCs occurred primarily at CG sites, followed by CHG sites and CHH sites. Compared to the control, melatonin treatment broadly decreased methylation levels at CHG and particularly CHH sites in various gene regions. Melatonin treatment generated a total of 25,125 differentially methylated regions (DMRs), which included 6517 DMR-associated genes. RNA-Seq demonstrated that 2479 genes were upregulated, and 1072 genes were repressed by melatonin treatment. The evaluation of the interconnection of the DNA methylome and transcriptome identified 144 genes showing a negative correlation between promoter methylation and gene expression, which were primarily related to biotic stress responses and flavonoid biosynthesis. Additionally, the application of 5́-azacytidine and melatonin led to similar effects on mycelial growth of B. cinerea, berry decay rate and flavonoid biosynthesis. Moreover, EDS1 was used to show that melatonin increased gene expression by decreasing promoter methylation levels. CONCLUSION: Our results demonstrated that melatonin broadly decreased DNA methylation and altered gene expression in grape berries. We propose that melatonin increases disease resistance and flavonoid biosynthesis by decreasing the methylation levels of the promoters of the genes involved.


Assuntos
Metilação de DNA/efeitos dos fármacos , Resistência à Doença/efeitos dos fármacos , Flavonoides/biossíntese , Expressão Gênica/efeitos dos fármacos , Melatonina/metabolismo , Doenças das Plantas/imunologia , Vitis/imunologia , Frutas/metabolismo , Genes de Plantas/efeitos dos fármacos , Melatonina/administração & dosagem , Reguladores de Crescimento de Plantas/metabolismo , Imunidade Vegetal/efeitos dos fármacos , Proteínas de Plantas/metabolismo
12.
Nanotechnology ; 31(14): 145703, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-31835264

RESUMO

Eutectic gallium-indium (EGaIn) alloy is a kind of liquid metal and has attracted much attention due to good properties. In order to satisfy the trend of miniaturization and realize more practical applications, the exploration for preparation method and properties of EGaIn at nanoscale are very important. Here, facile vacuum thermal evaporation method is developed to fabricate EGaIn nanostructures. The EGaIn nanoparticle and nanofilm with naturally formed 5 nm thick oxide layers are well prepared. The oxide film formed on the EGaIn surface is an important factor, making the properties of the nanostructure different from the properties of the bulk. Compared with ignorance of oxide layer in bulk materials, the proportion of oxide layer increases evidently in nanostructures, which produce obvious influence on the electric and optical properties. The rectifying characteristic and optoelectronic performance are experimentally observed. The EGaIn nanostructures can generate evident photocurrent responses with good responsivities (∼1 mA W-1) and response speed (∼1 s) under irradiation of 206 nm, 405 nm, 532 nm, 635 nm, 808 nm, 1064 nm and 10.6 µm lasers. These properties are completely different from the metallic properties of EGaIn bulk material.

13.
BMC Plant Biol ; 19(1): 383, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481025

RESUMO

BACKGROUND: Organic acid secretion is a widespread physiological response of plants to alkalinity. However, the characteristics and underlying mechanism of the alkali-induced secretion of organic acids are poorly understood. RESULTS: Oxalate was the main organic acid synthesized and secreted in grapevine (a hybrid of Vitis amurensis, V. berlandieri and V. riparia) roots, while acetate synthesis and malate secretion were also promoted under NaHCO3 stress. NaHCO3 stress enhanced the H+ efflux rate of grapevine roots, which is related to the plasma membrane H+-ATPase activity. Transcriptomic profiling revealed that carbohydrate metabolism was the most significantly altered biological process under NaHCO3 stress; a total of seven genes related to organic acid metabolism were significantly altered, including two phosphoenolpyruvate carboxylases and phosphoenolpyruvate carboxylase kinases. Additionally, the expression levels of five ATP-binding cassette transporters, particularly ATP-binding cassette B19, and two Al-activated malate transporter 2 s were substantially upregulated by NaHCO3 stress. Phosphoproteomic profiling demonstrated that the altered phosphoproteins were primarily related to binding, catalytic activity and transporter activity in the context of their molecular functions. The phosphorylation levels of phosphoenolpyruvate carboxylase 3, two plasma membrane H+-ATPases 4 and ATP-binding cassette B19 and pleiotropic drug resistance 12 were significantly increased. Additionally, the inhibition of ethylene synthesis and perception completely blocked NaHCO3-induced organic acid secretion, while the inhibition of indoleacetic acid synthesis reduced NaHCO3-induced organic acid secretion. CONCLUSIONS: Our results demonstrated that oxalate was the main organic acid produced under alkali stress and revealed the necessity of ethylene in mediating organic acid secretion. Additionally, we further identified several candidate genes and phosphoproteins responsible for organic acid metabolism and secretion.


Assuntos
Proteínas de Plantas/genética , Proteoma/genética , Bicarbonato de Sódio/metabolismo , Transcriptoma , Vitis/genética , Vitis/metabolismo , Ácidos/metabolismo , Compostos Orgânicos/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Proteoma/metabolismo
14.
ACS Appl Mater Interfaces ; 11(7): 7600-7606, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30698004

RESUMO

Graphene is receiving significant attention for use in optoelectronic devices because it exhibits a wide range of desirable electrical properties. Although modified graphene that is fabricated on quantum dots (or similar integration strategies) has shown promise, it has not met the requirements for high-speed applications and highly sensitive detection. Herein, we report ion-modulated graphene composite nanostructures that were incorporated into photodetectors. We focus on the dynamical properties of the novel photodetectors, and they exhibit extraordinary photoelectric performances (photoresponsivity ∼1 A/W, response time ∼100 µs) over a broad range of wavelengths from 405 to 1064 nm (the maximum external quantum efficiency is greater than 300% at 635 nm with a 10 kHz chopping frequency). A theoretical model is proposed in this paper, and it is in good agreement with our experimental results. The dynamic analyses further confirmed the dissociation and recombination of ion-electron bound states to be responsible for the fast and sensitive photoresponse from the composite samples. Although ion-modulated optoelectronic nanomaterials are rarely studied, they require further exploration as they offer new insights and alternatives in nanomaterial research.

15.
Cell Prolif ; 52(1): e12530, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30334302

RESUMO

OBJECTIVES: In vitro differentiation of oocytes from female germline stem cells (FGSCs) has exciting potential applications for reproductive medicine. Some researchers have attempted to reveal the in vitro differentiation capacity of FGSCs. However, no systematic comparative study of in vitro differentiation conditions has been performed for murine FGSCs (mFGSCs). MATERIALS AND METHODS: mFGSCs line was cultured under five different conditions for in vitro differentiation. RT-PCR was performed to detect the expression of Oct4, Fragilis, Blimp1, Mvh, Scp3 and Zp3. Immunofluorescence was carried out to test the expression of Mvh, Fragilis and Zp3. Two-photon laser-scanning microscope was used to analyze nucleus-plasma ratio, and the proportion of chromatin of GV oocytes differentiated from mFGSCs in vitro (IVD-GVO), GV oocytes from in vivo (GVO) and mFGSCs. RESULTS: RT-PCR and immunofluorescence showed that mFGSC line expressed germ cell-specific markers, but not a meiosis-specific marker. By evaluating five different in vitro differentiation conditions, condition 5, which included a hanging drop procedure and co-culture of mFGSCs with granulosa cells, was shown to be optimal. mFGSCs could be successfully differentiated into germinal vesicle (GV) -stage oocytes under this condition. 3D observation revealed that both the nucleus-plasma ratio and proportion of chromatin were not significantly different between IVD-GVO and GVO. CONCLUSION: We evaluated five in vitro differentiation conditions for mFGSCs and successfully differentiate mFGSCs into GV-stage oocytes using a three-step differentiation process.


Assuntos
Células da Granulosa/citologia , Oócitos/citologia , Oogênese/fisiologia , Animais , Técnicas de Cultura de Células , Proteínas de Ciclo Celular , Células Cultivadas , RNA Helicases DEAD-box/biossíntese , Proteínas de Ligação a DNA , Feminino , Proteínas de Membrana/biossíntese , Camundongos , Proteínas Nucleares/biossíntese , Fator 3 de Transcrição de Octâmero/biossíntese , Fator 1 de Ligação ao Domínio I Regulador Positivo/biossíntese , Glicoproteínas da Zona Pelúcida/biossíntese
16.
Nanotechnology ; 30(2): 025602, 2019 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-30411715

RESUMO

Herein, we propose a new strategy to fabricate gold (Au) micro/nanostructure arrays by photocatalytic solid-state electrochemical reaction between superionic conductor RbAg4I5 and Au films. The Au and RbAg4I5 films were successively deposited on a clean quartz substrate by vacuum thermal deposition method. A copper microgrid possessing periodic holes 100 µm in diameter was put above the RbAg4I5 film as a mask plate, whereupon irradiation from a 405 nm wavelength laser was used to diffuse gold ions (Au+ ions) into vacant silver sites of RbAg4I5 and transfer Au+ through ion passageways in the RbAg4I5 film. When the laser was turned off, the Au+ ions were easily reduced due to low activity compared to the silver (Ag+) ions. After multiple on/off cycles of the 405 nm laser, the irradiated area of uniform Au film exhibited a periodic structural unit array whose period was the same as that of the mask plate hole array. Atomic force microscope and scanning electron microscope images revealed that a self-assembled needle-like nanostructure array grew perpendicular to the substrate surface inside each circle's structural unit. The height of the grown nanostructure array increased with laser power density. Raman enhancement of the gold nanostructure array as substrate was detected using Rhodamine 6G (R6G) ethanol solutions as probe molecules. The enhancement effect increased with the height of the grown nanostructure array, and could increase by two orders of magnitude greater than that of unirradiated Au film. This strategy offers a new method for the micro/nanostructure processing of gold and provides microscale-array-mediated surface-enhancement Raman-scattering (SERS) substrates comprising Au nanostructures for application in high-sensitivity spectrum analysis.

17.
ACS Appl Mater Interfaces ; 10(42): 36304-36311, 2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30264557

RESUMO

Ultra-broad spectral detection is critical for several technological applications in imaging, sensing, spectroscopy, and communication. Carbon nanotube (CNT) films are a promising material for ultra-broadband photodetectors because their absorption spectra cover the entire ultraviolet to the terahertz range. However, because of the high binding energy of excitons, photodetectors based on CNT films always require a strong electric field, asymmetric electrical contacts, or hybrid structures with other materials. Here, we report an ultra-broadband bolometric photodetector based on a suspended CNT film. With an abundant distribution of tube diameters and an appropriate morphology (spider web-like), the CNT films display a strong absorption spectrum from the ultraviolet up to the terahertz region. Under illumination, heat generated from the electron-photon interaction dominates the photoresponse of our devices. For small changes in temperature, the photocurrent shows a convincing linear dependence with the absorbed light's power across 3 orders of magnitude. When the channel length is reduced to 100 µm, the device demonstrates a high performance with an ultraviolet responsivity of up to 0.58 A/W with a bias voltage of 0.2 V and a short response time of ∼150 µs in vacuum, which is better than that of many other photodetectors based on CNTs. Moreover, this performance could be further enhanced by optimization.

18.
Oncol Lett ; 16(4): 4656-4662, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30214600

RESUMO

Acute myeloid leukemia associated with t(8;21)(q22;q22)/runt related transcription factor (RUNX)1-RUNX1 translocation partner 1 has been reported to exhibit a favorable outcome. The quantitative polymerase chain reaction is a reliable method for assessing minimal residual disease persistence, and peripheral blood (PB) samples are as informative as bone marrow (BM) samples during follow-up monitoring. However, few studies have compared the spatial organization of leukemia-specific chromosomes between BM and PB. In the present study, paired BM and PB samples were extracted from 6 patients with acute myeloid leukaemia-M2 and compared using three-dimensional fluorescence in situ hybridization. Cells were classified into three types: Normal, proximal and malignant. Comparisons of proportions (% of all cells) of different cell types revealed no significant difference between BM and PB samples. The relative radial positions (RRPs; d/R) of chromosomes 8 and 21 were consistent for 2/3 of BM and PB samples. The RRPs of chromosomes in proximal pairs were more interior in nuclei compared with chromosomes in normal pairs for BM and PB samples. The consistency of the spatial organization of chromosomes between BM and PB suggests that PB may be an alternative to BM for research and clinical diagnosis.

20.
Sci Rep ; 6: 24503, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-27094084

RESUMO

Silver nanostructured films suitable for use as surface-enhanced Raman scattering (SERS) substrates are prepared in just 2 hours by the solid-state ionics method. By changing the intensity of the external direct current, we can readily control the surface morphology and growth rate of the silver nanostructured films. A detailed investigation of the surface enhancement of the silver nanostructured films using Rhodamine 6G (R6G) as a molecular probe revealed that the enhancement factor of the films was up to 10(11). We used the silver nanostructured films as substrates in SERS detection of human red blood cells (RBCs). The SERS spectra of RBCs on the silver nanostructured film could be clearly detected at a laser power of just 0.05 mW. Comparison of the SERS spectra of RBCs obtained from younger and older donors showed that the SERS spectra depended on donor age. A greater proportion of the haemoglobin in the RBCs of older donors was in the deoxygenated state than that of the younger donors. This implies that haemoglobin of older people has lower oxygen-carrying capacity than that of younger people. Overall, the fabricated silver substrates show promise in biomedical SERS spectral detection.


Assuntos
Técnicas Biossensoriais , Eritrócitos , Nanoestruturas/química , Prata/química , Análise Espectral Raman , Eritrócitos/metabolismo , Hemoglobinas/metabolismo , Nanoestruturas/ultraestrutura , Oxigênio/metabolismo , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...