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1.
Physiol Plant ; 176(4): e14465, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39126176

RESUMEN

Sugar is vital for plant growth and determines fruit quality via its content and composition. This study explores the differential sugar accumulation in two plum varieties, 'Fengtangli (FTL)' and 'Siyueli (SYL)'. The result showed that 'FTL' fruit displayed higher soluble solids and sugar content at various development stages. Metabolomic analysis indicated increased sorbitol in 'FTL', linked to elevated sorbitol-6-phosphate-dehydrogenase (S6PDH) activity. Transcriptome analysis identified a key gene for sorbitol synthesis, PsS6PDH4, which was significantly higher expressed in 'FTL' than in 'SYL'. The function of the PsS6PDH4 gene was verified in strawberry, apple, and plum fruits using transient overexpression and virus-induced gene silencing techniques. The results showed that overexpression of the PsS6PDH4 gene in strawberry, apple, and plum fruits promoted the accumulation of soluble solids content and sorbitol, while inhibition of the gene reduced soluble solids content and sorbitol content. Meanwhile, analysis of the relationship between PsS6PDH4 gene expression, sorbitol, and soluble solids content in four different plum varieties revealed a significant correlation between PsS6PDH4 gene expression and soluble solids content as well as sorbitol content. This research discovered PsS6PDH4 as a crucial regulator of sugar metabolism in plum, with potential applications in improving fruit sweetness and nutritional value in various fruit species. Understanding these molecular pathways can lead to innovative approaches for enhancing fruit quality, benefiting sustainable agriculture and consumer preferences in the global fruit industry.


Asunto(s)
Frutas , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Prunus domestica , Sorbitol , Sorbitol/metabolismo , Prunus domestica/genética , Prunus domestica/metabolismo , Frutas/genética , Frutas/metabolismo , Frutas/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Fragaria/genética , Fragaria/metabolismo , Azúcares/metabolismo , Malus/genética , Malus/metabolismo
2.
Nat Nanotechnol ; 19(10): 1452-1459, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39039120

RESUMEN

In the presence of a high magnetic field, quantum Hall systems usually host both even- and odd-integer quantized states because of lifted band degeneracies. Selective control of these quantized states is challenging but essential to understand the exotic ground states and manipulate the spin textures. Here we demonstrate the quantum Hall effect in Bi2O2Se thin films. In magnetic fields as high as 50 T, we observe only even-integer quantum Hall states, but there is no sign of odd-integer states. However, when reducing the thickness of the epitaxial Bi2O2Se film to one unit cell, we observe both odd- and even-integer states in this Janus (asymmetric) film grown on SrTiO3. By means of a Rashba bilayer model based on the ab initio band structures of Bi2O2Se thin films, we can ascribe the only even-integer states in thicker films to the hidden Rasbha effect, where the local inversion-symmetry breaking in two sectors of the [Bi2O2]2+ layer yields opposite Rashba spin polarizations, which compensate with each other. In the one-unit-cell Bi2O2Se film grown on SrTiO3, the asymmetry introduced by the top surface and bottom interface induces a net polar field. The resulting global Rashba effect lifts the band degeneracies present in the symmetric case of thicker films.

3.
J Am Chem Soc ; 146(30): 20837-20844, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39034718

RESUMEN

The synthesis of high-dielectric-constant (high-κ) dielectric materials and their integration with channel materials have been the key challenges in the state-of-the-art transistor architecture, as they can provide strong gate control and low operating voltage. For next-generation electronics, high-mobility two-dimensional (2D) layered semiconductors with dangling-bond-free surfaces and an atomic-thick thickness are being explored as channel materials to achieve shorter channel lengths and less interfacial scattering. Nowadays, the integration of high-κ dielectrics with high-mobility 2D semiconductors mainly relies on atomic layer deposition or transfer stacking, which may cause several undesirable problems, such as channel damage and interface traps. Here, we demonstrate the integration of high-mobility 2D semiconducting Bi2O2Se with transferable high-κ SrTiO3 as a 2D field-effect transistor by direct epitaxial growth. Remarkably, such 2D heterostructures can be efficiently transferred from the water-soluble Sr3Al2O6 sacrificial layer onto arbitrary substrates. The as-fabricated 2D Bi2O2Se/SrTiO3 transistors exhibit an on/off ratio over 104 and a subthreshold swing down to 90 mV/dec. Furthermore, the 2D Bi2O2Se/SrTiO3 heterostructures can be easily transferred onto flexible polyethylene terephthalate (PET) substrates, and the as-fabricated transistors exhibit good potential in flexible electronics. Our study opens up a new avenue for the integration of high-κ dielectrics with high-mobility 2D semiconductors and paves the way for the exploration of multifunctional electronic devices.

4.
Sensors (Basel) ; 24(4)2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38400355

RESUMEN

The frequent occurrence of extreme climate events has a significant impact on people's lives. Heavy rainfall can lead to an increase of regional Terrestrial Water Storage (TWS), which will cause land subsidence due to the influence of hydrological load. At present, regional TWS is mostly obtained from Gravity Recovery and Climate Experiment (GRACE) data, but the method has limitations for small areas. This paper used water level and flow data as hydrological signals to study the land subsidence caused by heavy rainfall in the Chaohu Lake area of East China (June 2016-August 2016). Pearson's correlation coefficient was used to study the interconnection between water resource changes and Global Navigation Satellites System (GNSS) vertical displacement. Meanwhile, to address the reliability of the research results, combined with the Coefficient of determination method, the research findings were validated by using different institutional models. The results showed that: (1) During heavy rainfall, the vertical displacement caused by atmospheric load was larger than non-tidal oceanic load, and the influence trends of the two were opposite. (2) The rapidly increasing hydrologic load in the Chaohu Lake area resulted in greater subsidence displacement at the closer CORS station (CHCH station) than the more distant CORS station (LALA station). The Pearson correlation coefficients between the vertical displacement and water level were as high as -0.80 and -0.64, respectively. The phenomenon confirmed the elastic deformation principle of disc load. (3) Although there was a systematic bias between the different environmental load deformation models, the deformation trends were generally consistent with the GNSS monitoring results. The average Coefficients of determination between the different models and the GNSS results were 0.63 and 0.77, respectively. The results demonstrated the effectiveness of GNSS in monitoring short-term hydrological load. This study reveals the spatial-temporal evolution of land deformation during heavy rainfall around Chaohu Lake, which is of reference significance for water resource management and infrastructure maintenance in this area.

5.
Nat Mater ; 22(7): 832-837, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36894772

RESUMEN

The scaling of silicon-based transistors at sub-ten-nanometre technology nodes faces challenges such as interface imperfection and gate current leakage for an ultrathin silicon channel1,2. For next-generation nanoelectronics, high-mobility two-dimensional (2D) layered semiconductors with an atomic thickness and dangling-bond-free surfaces are expected as channel materials to achieve smaller channel sizes, less interfacial scattering and more efficient gate-field penetration1,2. However, further progress towards 2D electronics is hindered by factors such as the lack of a high dielectric constant (κ) dielectric with an atomically flat and dangling-bond-free surface3,4. Here, we report a facile synthesis of a single-crystalline high-κ (κ of roughly 16.5) van der Waals layered dielectric Bi2SeO5. The centimetre-scale single crystal of Bi2SeO5 can be efficiently exfoliated to an atomically flat nanosheet as large as 250 × 200 µm2 and as thin as monolayer. With these Bi2SeO5 nanosheets as dielectric and encapsulation layers, 2D materials such as Bi2O2Se, MoS2 and graphene show improved electronic performances. For example, in 2D Bi2O2Se, the quantum Hall effect is observed and the carrier mobility reaches 470,000 cm2 V-1 s-1 at 1.8 K. Our finding expands the realm of dielectric and opens up a new possibility for lowering the gate voltage and power consumption in 2D electronics and integrated circuits.


Asunto(s)
Grafito , Silicio , Electrónica , Semiconductores
6.
Int J Mol Sci ; 23(19)2022 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-36232825

RESUMEN

Horticultural products display fast senescence after harvest at ambient temperatures, resulting in decreased quality and shorter shelf life. As a gaseous signal molecule, nitric oxide (NO) has an important physiological effect on plants. Specifically, in the area of NO and its regulation of postharvest senescence, tremendous progress has been made. This review summarizes NO synthesis; the effect of NO in alleviating postharvest senescence; the mechanism of NO-alleviated senescence; and its interactions with other signaling molecules, such as ethylene (ETH), abscisic acid (ABA), melatonin (MT), hydrogen sulfide (H2S), hydrogen gas (H2), hydrogen peroxide (H2O2), and calcium ions (Ca2+). The aim of this review is to provide theoretical references for the application of NO in postharvest senescence in horticultural products.


Asunto(s)
Sulfuro de Hidrógeno , Melatonina , Ácido Abscísico , Calcio , Etilenos , Hidrógeno , Peróxido de Hidrógeno , Sulfuro de Hidrógeno/farmacología , Melatonina/farmacología , Óxido Nítrico
7.
Materials (Basel) ; 15(7)2022 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-35407976

RESUMEN

The powder metallurgy process of the Al-graphene system is conducted by molecular dynamics (MD) simulations to investigate the role of graphene. During the sintering process, graphene is considered to reduce the pore size and metal grain size based on the volume change and atomic configuration of the Al parts in the composite. Compared with the pure Al system, the space occupied by the same number of Al atoms in the sintered composite is 15-20 nm3 smaller, and the sintered composite has about 5000 fewer arranged atoms. Because these models are carefully designed to avoid a serious deformation of graphene in the tension of sandwich-like composite models, the strengthening mechanism close to the experimental theory where graphene just serves to transfer a load can be studied dynamically. The boundary comprising of two phases is confirmed to hinder the motion of dislocations, while the crack grows along the interface beside graphene, forming a fracture surface of orderly arranged Al atoms. The results indicate that single-layer graphene (SLG) gives rise to an increase of 1.2 or 0.4 GPa in tensile strength when stretched in in-plane or normal direction, while bilayer graphene (BLG) brings a clear rise of 1.2-1.3 GPa in both directions. In both in-plane and normal stretching directions, the mechanical properties of the composite can be improved clearly by graphene giving rise to a strong boundary, new crack path, and more dense structure.

8.
Materials (Basel) ; 15(6)2022 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-35329739

RESUMEN

With the rapid development of modern industries, the surface quality and performance of metals need to be improved. Composite electrodeposition (co-deposition) has evolved as an important technique for improving the surface performance of metal materials. Herein, a new type of graphene oxide (GO)-reinforced nickel-boron (Ni-B) composite coating was successfully prepared on a 7075 aluminum (Al) alloy by co-deposition. Characterization revealed a significant improvement in the mechanical and anti-corrosion properties of the composite with the incorporation of GOs. The composite showed a rougher, compact, cauliflower-like morphology with finer grains, a higher hardness (1532 HV), a lower rate of wear (5.20 × 10-5 mm3∙N-1∙m-1), and a lower corrosion rate (33.66 × 10-3 mm∙y-1) compared with the Ni-B alloy deposit (878 HV, 9.64 × 10-5 mm3∙N-1∙m-1, and 116.64 × 10-3 mm∙y-1, respectively). The mechanism by which GOs strengthen the Ni-B matrix is discussed.

9.
Foods ; 10(7)2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-34359390

RESUMEN

Various microencapsulation techniques can result in significant differences in the properties of dried microcapsules. Microencapsulation is an effective approach to improve fish oil properties, including oxidisability and unpleasant flavour. In this study, ß-carotene, lutein, zeaxanthin, and fish oil were co-encapsulated by microfluidic-jet spray drying (MFJSD), two-fluid nozzle spray drying (SD), and freeze-drying (FD), respectively. The aim of the current study is to understand the effect of different drying techniques on microcapsule properties. Whey protein isolate (WPI) and octenylsuccinic anhydride (OSA) modified starch were used as wall matrices in this study for encapsulating carotenoids and fish oil due to their strong emulsifying properties. Results showed the MFJSD microcapsules presented uniform particle size and regular morphological characteristics, while the SD and FD microcapsules presented a large distribution of particle size and irregular morphological characteristics. Compared to the SD and FD microcapsules, the MFJSD microcapsules possessed higher microencapsulation efficiency (94.0-95.1%), higher tapped density (0.373-0.652 g/cm3), and higher flowability (the Carr index of 16.0-30.0%). After a 4-week storage, the SD microcapsules showed the lower retention of carotenoids, as well as ω-3 LC-PUFAs than the FD and MFJSD microcapsules. After in vitro digestion trial, the differences in the digestion behaviours of the microcapsules mainly resulted from the different wall materials, but independent of drying methods. This study has provided an alternative way of delivering visual-beneficial compounds via a novel drying method, which is fundamentally essential in both areas of microencapsulation application and functional food development.

10.
Foods ; 10(1)2021 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-33435574

RESUMEN

This study aimed to offer an alternative way for delivering the benefits of the mandarin fruit juice to consumers via spray drying microencapsulation. Two mandarin cultivars, Afourer (A) and Richard Special (RS), were studied. Three types of juice sample were prepared, i.e., the whole fruit juice (A3 & RS3), the flavedo-removed fruit juice (A2 & RS2), and the peel-removed fruit juice (A1 & RS1) samples. Gum Acacia and maltodextrin (ratio of 1:1, w/w) were chosen as wall matrices for aiding the drying of the juice samples while using a microfluidic-jet spray dryer. The properties of the fruit powder (colour, water activity, bulk/trapped density, solubility, hygroscopicity, morphology) and the retention of major phytochemicals (i.e., phenolic and volatile compounds) were examined. The results showed that the powders produced from the whole fruit juices (A3 and RS3) gave higher yellow colour with a regular winkled surface than other powders (A1 & RS1, and A2 & RS2). The water activity of mandarin powders was in a range of 0.14 to 0.25, and the solubility was around 74% with no significant difference among all of the powders. The whole fruit powders had a significantly higher concentration of phenolic compounds (A3, 1023 µg/100 mg vs. A2, 809 µg/100 mg vs. A1, 653 µg/100 mg) and aroma compounds (A3, 775,558 µg/L vs. A2, 125,617 µg/L vs. A1, 12,590 µg/L). This study contributed to the delivery of phenolic and flavour compounds of the mandarin fruits, at the same time minimising waste generation during processing. It also gave insight into the production of spray-dried powders from the whole mandarin fruits.

11.
Sci Rep ; 10(1): 10684, 2020 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-32606437

RESUMEN

Food security in China is under additional stress due to climate change. The risk analysis of maize yield losses is crucial for sustainable agricultural production and climate change impact assessment. It is difficult to quantify this risk because of the constraints on the high-resolution data available. Moreover, the current results lack spatial comparability due to the area effect. These challenges were addressed by using long-term county-level maize yield and planting area data from 1981 to 2010. We analyzed the spatial distribution of maize yield loss risks in mainland China. A new comprehensive yield loss risk index was established by combining the reduction rate, coefficient of variation, and probability of yield reduction after removing the area effect. A total of 823 counties were divided into areas of lowest, low, moderate, high, and highest risk. High risk in maize production occurred in Heilongjiang and Jilin Provinces, the eastern part of Inner Mongolia, the eastern part of Gansu-Xinjiang, west of the Loess Plateau, and the western part of the Xinjiang Uygur Autonomous Region. Most counties in Northeast China were at high risk, while the Loess Plateau, middle and lower reaches of the Yangtze River and Gansu-Xinjiang were at low risk.


Asunto(s)
Productos Agrícolas/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo , Agricultura/métodos , China , Cambio Climático , Seguridad Alimentaria/métodos , Probabilidad , Riesgo
12.
Sci Rep ; 10(1): 6749, 2020 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-32317717

RESUMEN

Due to many factors in the physical properties of the ground surface, the corresponding interferometric coherence values change dynamically over time. Among these factors, the roles of the vegetation and its temporal variation have not yet been revealed so far. In this paper, synthetic aperture radar (Sentinel-1) data and optical remote sensing (Landsat TM) images over four whole seasons are employed to reveal the relationship between the interferometric coherence and the normalized difference vegetation index (NDVI) at five sites that have ground deformation due to mining in Henan province, China. The result showed: (1) As for the village area with few vegetation cover, the related coherence values are significantly higher than that in the farm land area with high densities of vegetation in the spring and summer, which indicates that the subsidence by mining in few vegetation cover area is easier to be monitored; (2) Linear regression coefficients ([Formula: see text]) between the interfereometric coherence values and the NDVI values is 0.62, which indicate the interferometric coherence values and the NDVI values change reversely in both farm land and village areas over the year. It suggests months between November and March with lower NDVI value are more suitable for deformation detecting. Therefore, the interfereometric coherence values can be used to detect the density of vegetation, while NDVI values can be reference for elucidating when the traditional differential interferometric synthetic aperture radar (DInSAR) could be effectively used.

13.
Plant J ; 102(5): 965-976, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31923329

RESUMEN

Anthocyanin biosynthesis is induced by low temperatures in a number of plants. However, in peach (cv Zhonghuashoutao), anthocyanin accumulation was observed in fruit stored at 16°C but not at or below 12°C. Fruit stored at 16°C showed elevated transcript levels of genes encoding anthocyanin biosynthetic enzymes, the transport protein glutathione S-transferase and key transcription factors. Higher transcript levels of PpPAL1/2, PpC4H, Pp4CL4/5/8, PpF3H, PpF3'H, PpDFR1/2/3 and PpANS, as well as transcription factor gene PpbHLH3, were associated with lower methylation levels in the promoter of these genes. The DNA methylation level was further highly correlated with the expression of the DNA methyltransferase genes and DNA demethylase genes. The application of DNA methylation inhibitor 5-azacytidine induced anthocyanin accumulation in peach flesh, further implicating a critical role for DNA demethylation in regulating anthocyanin accumulation in peach flesh. Our data reveal that temperature-dependent DNA demethylation is a key factor to the post-harvest temperature-dependent anthocyanin accumulation in peach flesh.


Asunto(s)
Antocianinas/metabolismo , Proteínas de Plantas/metabolismo , Prunus persica/metabolismo , Desmetilación del ADN , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Proteínas de Plantas/genética , Prunus persica/genética , Temperatura
14.
Plant Biotechnol J ; 18(5): 1284-1295, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31693790

RESUMEN

Anthocyanins have crucial biological functions and affect quality of horticultural produce. Anthocyanins accumulate in ripe peach fruit; differential accumulation is observed in deep coloured cultivar 'Hujingmilu' and lightly pigmented cultivar 'Yulu'. The difference was not fully explained by accumulation of total flavonoids and expression of anthocyanin biosynthetic genes. Expression analysis was conducted on a glutathione S-transferase gene (PpGST1), and it was found that the expression correlated well with anthocyanin accumulation in peach fruit tissues. Functional complementation of the Arabidopsis tt19 mutant indicated that PpGST1 was responsible for transport of anthocyanins but not proanthocyanidins. PpGST1 was localized in nuclei and the tonoplast, including the sites at which anthocyanin vacuolar sequestration occurred. Transient overexpression of PpGST1 together with PpMYB10.1 in tobacco leaves and peach fruit significantly increased anthocyanin accumulation as compared with PpMYB10.1 alone. Furthermore, virus-induced gene silencing of PpGST1 in a blood-fleshed peach not only resulted in a reduction in anthocyanin accumulation but also a decline in expression of anthocyanin biosynthetic and regulatory genes. Cis-element analysis of the PpGST1 promoter revealed the presence of four MYB binding sites (MBSs). Dual-luciferase assays indicated that PpMYB10.1 bound to the promoter and activated the transcription of PpGST1 by recognizing MBS1, the one closest to the ATG start codon, with this trans-activation being stronger against the promoter of deep coloured 'Hujingmilu' compared with lightly coloured cultivar 'Yulu'. Altogether, our data provided molecular evidence supporting coordinative regulatory roles of PpGST1 and PpMYB10.1 in anthocyanin accumulation in peach.


Asunto(s)
Prunus persica , Antocianinas , Frutas/genética , Frutas/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus persica/genética , Prunus persica/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
15.
Cells ; 8(12)2019 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-31835827

RESUMEN

Peach is prone to postharvest chilling injury (CI). Here it was found that exogenous ethylene alleviated CI, accompanied by an increased endogenous ethylene production. Ethylene treatment resulted in a moderately more rapid flesh softening as a result of stronger expression of genes encoding expansin and cell wall hydrolases, especially xylosidase and galactosidase. Ethylene treatment alleviated internal browning, accompanied by changes in expression of polyphenol oxidase, peroxidase and lipoxygenases. An enhanced content of phospholipids and glycerolipids and a reduced content of ceramide were observed in ethylene-treated fruit, and these were associated with up-regulation of lipid phosphate phosphatase, fatty acid alpha-hydroxylase, and golgi-localized nucleotide sugar transporter, as well as down-regulation of aminoalcoholphosphotransferases. Expression of two ethylene response factors (ERFs), ESE3 and ABR1, was highly correlated with that of genes involved in cell wall metabolism and lipid metabolism, respectively. Furthermore, the expression of these two ERFs was strongly regulated by ethylene treatment and the temperature changes during transfer of fruit into or out of cold storage. It is proposed that ERFs fulfill roles as crucial integrators between cell wall modifications and lipid metabolism involved in CI processes ameliorated by exogenous ethylene.


Asunto(s)
Etilenos/farmacología , Metabolismo de los Lípidos/efectos de los fármacos , Proteínas de Plantas/genética , Prunus persica/fisiología , Catecol Oxidasa/genética , Pared Celular/efectos de los fármacos , Pared Celular/genética , Frío , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Lipooxigenasas/genética , Peroxidasa/genética , Prunus persica/efectos de los fármacos , Estrés Fisiológico
16.
Molecules ; 23(12)2018 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-30486276

RESUMEN

Targeted drug delivery to colon cancer cells can significantly improve the efficiency of treatment. We firstly synthesized carboxyl-modified mesoporous silica nanoparticles (MSN⁻COOH) via two-step synthesis, and then developed calcium leucovorin (LV)-loaded carboxyl-modified mesoporous silica nanoparticles based on galactosylated chitosan (GC), which are galectin receptor-mediated materials for colon-specific drug delivery systems. Both unmodified and functionalized nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), nitrogen sorption, and dynamic light scattering (DLS). Drug release properties and drug loading capacity were determined by ultraviolet spectrophotometry (UV). LV@MSN⁻COOH/GC had a high LV loading and a drug loading of 18.07%. In vitro, its release, mainly by diffusion, was sustained release. Cell experiments showed that in SW620 cells with the galectin receptor, the LV@MSN⁻COOH/GC metabolized into methyl tetrahydrofolic acid (MTHF) and 5-fluorouracil (5-FU)@MSN⁻NH2/GC metabolized into FdUMP in vivo. MTHF and 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP) had combined inhibition and significantly downregulated the expression of thymidylate synthase (TS). Fluorescence microscopy and flow cytometry experiments show that MSN⁻COOH/GC has tumor cell targeting, which specifically recognizes and binds to the galectin receptor in tumor cells. The results show that the nano-dosing system based on GC can increase the concentrations of LV and 5-FU tumor cells and enhance their combined effect against colon cancer.


Asunto(s)
Quitosano/química , Neoplasias del Colon/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Galactosa/química , Leucovorina/uso terapéutico , Nanopartículas/química , Dióxido de Silicio/química , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Neoplasias del Colon/patología , Portadores de Fármacos/química , Liberación de Fármacos , Glicosilación , Humanos , Leucovorina/farmacología , Nanopartículas/ultraestructura , Porosidad , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Termogravimetría , Timidilato Sintasa/metabolismo
17.
Environ Sci Pollut Res Int ; 25(31): 31091-31100, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30187409

RESUMEN

The photochemical oxidation of di-n-butyl phthalate (DBP) by •OH radicals from nitrous acid (HONO) in atmospheric hydrometeors was explored by two techniques, steady-state irradiation, and laser flash photolysis (LFP). The effects of atmospheric liquid parameters on DBP transformation were systematically evaluated, showing that DBP does not react with HONO directly and •OH-initiated reactions are crucial steps for consumption and transformation of DBP. Two reaction channels are operative: •OH addition and hydrogen atom abstraction. The overall rate constant for the reaction of DBP with •OH is 5.7 × 109 M-1 s-1, and its specific rate constant for addition is 3.7 × 109 M-1 s-1 determined by using laser flash photolysis technique. Comparing the individual reaction rate constant for aromatic ring addition with the total rate constant, the majority of the •OH radicals (about 65%) attack the aromatic ring. The major transformation products were identified by GC-MS, and the trends of their yields derived from both ring addition and H-abstraction with time are discussed. These results provide important insights into the photochemical transformation of DBP in atmospheric hydrometeors and contribute to atmospheric aerosol chemistry.


Asunto(s)
Dibutil Ftalato/química , Radical Hidroxilo/química , Ácido Nitroso/química , Aerosoles , Cromatografía de Gases y Espectrometría de Masas , Cinética , Oxidación-Reducción
18.
R Soc Open Sci ; 5(12): 181027, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30662725

RESUMEN

Targeted drug delivery to colon cancer cells can significantly enhance the therapeutic efficiency. Herein, we developed 5-fluorouracil (5-FU)-loaded amino-functionalized mesoporous silica nanoparticle (MSN-NH2)-based galactosylated chitosans (GCs), which are galactose receptor-mediated materials for colon-specific drug delivery systems. Both unmodified and functionalized nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen sorption and dynamic light scattering. Drug loading capacity and drug release properties were determined by ultraviolet spectrophotometry. 5-FU@MSN-NH2/GC showed high loading capacity and possessed much higher cytotoxicity on human colon cancer cells (SW620 cells) than 5-FU@MSN-NH2 and free 5-FU. But, MSN-NH2/GC did not show significant cytotoxicity. Subsequently, 5-FU@MSN-NH2/GC anti-cancer activity on SW620 cells in vitro was confirmed by cell apoptosis. These results are consistent with the cellular uptake test in which MSN-NH2/GC could specifically recognize and bind to cancer cells by the galectin-receptor recognition. But, it is found that pre-addition of galactose in the medium, leading to competitive binding to the galectin receptor of SW620 cells, resulted in a decrease in the binding of MSN-NH2/GC to the galectin receptor. The results demonstrated the inorganic-organic nanocomposite could be used as a promising drug delivery carrier for the targeted delivery of drug into galectin-positive colon cancer cells to improve therapeutic index while reducing side effects.

19.
Sensors (Basel) ; 17(7)2017 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-28704948

RESUMEN

Global Navigation Satellite System (GNSS) signals can be exploited to remotely sense atmosphere and land and ocean surface to retrieve a range of geophysical parameters. This paper proposes two new methods, termed as power-summation of differential Delay-Doppler Maps (PS-D) and pixel-number of differential Delay-Doppler Maps (PN-D), to distinguish between sea ice and sea water using differential Delay-Doppler Maps (dDDMs). PS-D and PN-D make use of power-summation and pixel-number of dDDMs, respectively, to measure the degree of difference between two DDMs so as to determine the transition state (water-water, water-ice, ice-ice and ice-water) and hence ice and water are detected. Moreover, an adaptive incoherent averaging of DDMs is employed to improve the computational efficiency. A large number of DDMs recorded by UK TechDemoSat-1 (TDS-1) over the Arctic region are used to test the proposed sea ice detection methods. Through evaluating against ground-truth measurements from the Ocean Sea Ice SAF, the proposed PS-D and PN-D methods achieve a probability of detection of 99.72% and 99.69% respectively, while the probability of false detection is 0.28% and 0.31% respectively.

20.
J Food Sci ; 82(3): 781-786, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28182843

RESUMEN

The capabilities of red wine against lipid oxidation and angiogenesis were evaluated by using a fish oil emulsion system and an in vivo zebrafish embryos model, respectively. The red wine contained 12 different antioxidant phenolics which levels were led by anthocyanins (140.46 mg/L), catechin (55.08 mg/L), and gallic acid (46.76 mg/L). The diversity of the phenolics in red wine was greater than the tea, coffee, or white wine selected as a peer control in this study. The total phenolics concentration of red wine was 305.53 mg/L, although the levels of tea, coffee, and white wine were 85.59, 76.85, and 26.57 mg/L, respectively. The activity of red wine in scavenging DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals was approximately 4 times higher than the tea and 8 times than the coffee or white wine. The red wine showed the highest capability in preventing long chain PUFA oxidation in the fish oil emulsion. Because of the outstanding antioxidant activity of red wine, the red wine dried extract was used to monitor its inhibitory effect against angiogenesis by using transgenic zebrafish embryos (Tg[fli1:egfp]y1 ) with fluorescent blood vessels. After incubated in 100 µg/mL of the extract solution for 26 h pf, each of the embryos had a lower number of intersegmental vessel than the control embryo. The inhibition rate of red wine extract against growing of angiogenic blood vessel reached 100%.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antocianinas/farmacología , Antioxidantes/farmacología , Aceites de Pescado/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Fenoles/farmacología , Vino/análisis , Inhibidores de la Angiogénesis/análisis , Animales , Animales Modificados Genéticamente , Antocianinas/análisis , Antioxidantes/análisis , Compuestos de Bifenilo/metabolismo , Catequina/análisis , Emulsiones , Radicales Libres/metabolismo , Ácido Gálico/análisis , Oxidación-Reducción , Fenoles/análisis , Picratos/metabolismo , Extractos Vegetales/química , Extractos Vegetales/farmacología , Vitis/química , Pez Cebra/embriología
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