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1.
Langmuir ; 39(47): 16812-16824, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37965918

RESUMO

The deposition time was controlled to prepare Mn nanowires of different lengths and diameters on templates of anodic aluminum oxide (AAO) with different pore sizes. The surface of as-prepared Mn nanowires was modified with SiO2 using the sol-gel method to improve their dispersion in aqueous solution. The effects of the diameter and length of the as-prepared Mn nanowires coated with SiO2 on the relaxivity were investigated. It was found that the Mn@SiO2 nanowires have smaller diameters and a higher longitudinal relaxivity (r1) with an increased length. Mn3@SiO2 nanowires had the highest r1 value of 5.8 mM-1 s-1 among the Mn@SiO2 nanowires (Mn3 nanowires have a diameter of about 30 nm and a length of about 0.5 µm length). Additionally, the biocompatibility and in vivo imaging ability of the Mn3@SiO2 nanowires were evaluated. The Mn3@SiO2 nanowires had good cytotoxicity and biocompatibility, and the kidney of SD rats showed a positive enhancement effect during small animal imaging at 1.5 T. This study showed that the Mn3@SiO2 nanowires could potentially become contrast agents (CAs) of longitudinal relaxation time (T1).

2.
Discov Nano ; 18(1): 136, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37903989

RESUMO

A facile template method was employed to synthesize Fe nanowires of different sizes, dimensions. Comprehensive analyses were conducted to explore their morphology, structure, composition, and magnetic properties. The surface of as-prepared Fe nanowires was modified with SiO2 by sol-gel method to improve the dispersion of as-prepared Fe nanowires in aqueous solution. Furthermore, the relaxation properties, biocompatibility and in vivo imaging abilities of the Fe@SiO2 nanowires were evaluated. The study revealed that the SiO2-coated Fe nanowires functioned effectively as transverse relaxation time (T2) contrast agents (CAs). Notably, as the length of the Fe@SiO2 nanowires increased, their diameter decreased, leading to a higher the transverse relaxivity (r2) value. Our study identified that among the Fe nanowires synthesized, the Fe3@SiO2 nanowires, characterized by a diameter of around 30 nm and a length of approximately 500 nm, exhibited the highest r2 value of 59.3 mM-1 s-1. These nanowires demonstrated good biocompatibility and non-toxicity. Notably, upon conducting small animal imaging a 1.5 T with Sprague-Dawley rats, we observed a discernible negative enhancement effect in the liver. These findings indicate the promising potential of Fe@SiO2 nanowires as T2 CAs, with the possibility of tuning their size for optimized results.

3.
J Biomater Appl ; 38(2): 292-301, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37452613

RESUMO

The purpose of this study was to evaluate the astaxanthin-loaded nanostructured lipid carriers (ASX-NLC) prepared using a high-pressure homogenization transport system for local application of astaxanthin. Dynamic light scattering (DLS) and X-ray diffraction (XRD) were used to study the effect of microencapsulation on the properties of ASX-NLC. The mean size of ASX-NLC was about 108.43 ± 0.26 nm and PdI was 0.176 ± 0.002. The ASX-NLC had high encapsulation efficiency which was 95.69 ± 0.13%. Good light stability and temperature stability were shown at the ASX-NLC, indicating that the preparation process was feasible. The 2,2-diphenyl-1-pyridylohydrazinyl (DPPH) scavenging test showed that ASX-NLC could still play an antioxidant role. In vitro release studies showed that compared with an astaxanthin ethanol solution, an ASX-NLC could maintain astaxanthin release more effectively. In vitro permeation studies showed that ASX-NLC could increase astaxanthin retention in the skin. In conclusion, ASX-NLC could significantly enhance astaxanthin accumulation during dermal applications. The research results have important reference significance for local skin applications and provide a basis for the development of nanostructured lipid carriers. ASX-NLC might be suitable carriers for the local application of astaxanthin.


Assuntos
Antioxidantes , Nanoestruturas , Antioxidantes/química , Lipídeos/química , Portadores de Fármacos/química , Pele , Nanoestruturas/química , Tamanho da Partícula
4.
Artigo em Inglês | MEDLINE | ID: mdl-36231537

RESUMO

The Yellow River Basin serves as China's primary ecological barrier and economic belt. The achievement of the Yellow River Basin's "double carbon" objective is crucial to China's green and low-carbon development. This study examines the spatial link and network structure of city cluster carbon emission efficiency in the Yellow River Basin, as well as the complexity of the network structure. It focuses not only on the density and centrality of the carbon emission efficiency network from the standpoint of city clusters, but also on the excellent cities and concentration of the city cluster 's internal carbon emission efficiency network. The results show that: (1) The carbon emission efficiency of the Yellow River Basin has been dramatically improved, and the gap between city clusters is narrowing. However, gradient differentiation characteristics between city clusters show the Matthew effect. (2) The distribution of carbon emission efficiency in the Yellow River Basin is unbalanced, roughly showing a decreasing trend from east to west. Lower-level efficiency cities have played a significant role in the evolution of carbon emissions efficiency space. (3) The strength of the carbon emission efficiency network structure in the Yellow River Basin gradually transitions from weakly correlated dominant to weakly and averagely correlated dominant. Among them, the Shandong Peninsula city cluster has the most significant number of connected nodes in the carbon emission efficiency network. In contrast, the emission efficiency network density of the seven city clusters shows different changing trends. Finally, this study suggests recommendations to improve carbon emission efficiency by adopting differentiated governance measures from the perspective of local adaptation and using positive spatial spillover effects.


Assuntos
Carbono , Rios , Carbono/análise , China , Cidades , Desenvolvimento Econômico , Eficiência , Rios/química
5.
J Food Sci ; 87(10): 4596-4608, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36102167

RESUMO

Our objective was to investigate if the internal aqueous phase gelation of Water-in-oil-in-water double emulsions encapsulated in alginate beads would affect their structural stability and lipid hydrolysis during in vitro digestion. Therefore, bioactive molecules such as (-)-epigallocatechin gallate were encapsulated into different types of delivery systems: original double emulsions (as control) and incorporated double emulsions (filled in alginate hydrogel beads), both with non-gelled or gelled internal aqueous phase by locust bean gum and κ-carrageenan. After 2 h of gastric digestion, the gelled original emulsions showed smaller mean droplet diameters and less coalescence during the in vitro simulated gastrointestinal digestion compared to the non-gelled original emulsions. For the incorporated emulsions, oil droplets released from beads aggregated under intestinal conditions, and the rate of lipolysis was delayed. Interestingly, the internal aqueous phase gelation also impacted the rate and cumulative amount of free fatty acids (FFA) released. PRACTICAL APPLICATION: The combination of incorporating (-)-epigallocatechin gallate-loaded double emulsions into the alginate hydrogel matrix and gelling the internal aqueous phase was a benefit to regulating the rate and extent of lipid digestion for specific applications in foods, such as to control blood lipid levels and appetite.


Assuntos
Alginatos , Hidrogéis , Emulsões/química , Alginatos/química , Carragenina , Ácidos Graxos não Esterificados , Água/química , Digestão , Tamanho da Partícula
6.
Pharmacol Ther ; 237: 108254, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35870566

RESUMO

The human brain is specifically enriched for multiple classes of noncoding RNAs (ncRNAs) and for particular RNA modifications, both of which are increasingly recognized to contribute to the etiology and pathophysiology of psychiatric disorders. Here, we summarize the rapidly developing areas of basic research in brain-specific ncRNA biology and the functional and pathological consequences of different RNA modifications. In particular, multiple studies have identified mutual regulation between ncRNAs and RNA modifications. Specifically, RNA methylation of ncRNAs can regulate their cleavage and maturation, intracellular transport, stability, and ultimately their degradation. Alternatively, ncRNAs can affect RNA modifications by up- or down-regulating target protein expression or by altering their subcellular distribution, among several other effects. Growing clinical and preclinical research attention is currently being focused on exploring the pathological impacts and highly diverse molecular regulatory mechanisms of ncRNAs and RNA modifications in psychiatric disorders. Here, we review recent findings surrounding the mutual regulation between ncRNAs and RNA modifications in brain psychopathology. We also discuss advances in basic discovery and clinical translation or therapeutic potential of targeting ncRNAs and/or RNA modification regulators in psychiatric disorders.


Assuntos
Transtornos Mentais , RNA Longo não Codificante , Humanos , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/genética , Metilação , RNA Longo não Codificante/genética , RNA não Traduzido/genética , RNA não Traduzido/metabolismo
7.
Chem Phys Lipids ; 242: 105150, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34673008

RESUMO

Phloretin is a powerful antioxidant with many effects, such as anti-cancer, anti-inflammatory, promoting cell renewal, delaying aging and so on. However, the application of phloretin was limited by its low water solubility, low absorption in vivo and unstable properties. A phloretin-loaded nanostructured lipid carrier was designed with a high-pressure homogenization technique. The mean particle size of phloretin NLC was 137.40 ± 3.27 nm, and the Polydispersity index (PdI) value was 0.237 ± 0.005. The encapsulation efficiency was 96.68% ± 0.06%. Transmission electron microscopy images showed that the phloretin-loaded nanostructured lipid carriers were spherical. Phloretin in NLC showed a sustained release pattern in vitro. The results showed that phloretin NLC is more suitable for absorption than phloretin ethanol solution, and NLC can be a promising carrier for phloretin in the food industry.


Assuntos
Portadores de Fármacos , Nanoestruturas , Lipídeos , Tamanho da Partícula , Floretina
8.
ACS Appl Mater Interfaces ; 13(25): 29340-29348, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34137582

RESUMO

We demonstrate a versatile nanoparticle with imaging-guided chemo-photothermal synergistic therapy and EpCAM-targeted delivery of liver tumor cells. EpCAM antibody (anti-EpCAM) and Pt(IV) were grafted onto the polydopamine carbon dots (PDA-CDs) by the amidation reaction. The EpCAM antibody of particles enables the targeted interaction with liver progenitor cells due to their overexpressed EpCAM protein. The tetravalent platinum prodrug [Pt(IV)] induces apoptosis with minimum toxic side effects through the interaction between cisplatin and tumor cell DNA. The nanoparticles displayed stable photothermal property and considerable anti-tumor therapeutic effect in vivo. Coupling with cellular imaging due to their fluorescence property, anti-EpCAM@PDA-CDs@Pt(IV) offers a convenient and effective platform for imaging-guided chemo-photothermal synergistic therapy toward liver cancers in the near future.


Assuntos
Antineoplásicos , Molécula de Adesão da Célula Epitelial/metabolismo , Corantes Fluorescentes , Indóis , Polímeros , Pontos Quânticos , Animais , Anticorpos Imobilizados/química , Anticorpos Imobilizados/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Feminino , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacocinética , Corantes Fluorescentes/farmacologia , Células HeLa , Células Hep G2 , Humanos , Indóis/química , Indóis/farmacocinética , Neoplasias Hepáticas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Polímeros/química , Polímeros/farmacocinética , Pontos Quânticos/química , Pontos Quânticos/metabolismo , Nanomedicina Teranóstica/métodos
9.
Materials (Basel) ; 14(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925382

RESUMO

A lot of nanomaterials are using T1-T2 dual mode magnetic resonance (MR) contrast agents (CAs), but multilayer nanowire (NW) with iron (Fe) and manganese (Mn) as T1-T2 dual modal CAs has not been reported yet. Herein, we synthesized a Fe/Mn multilayer NW with an adjustable Fe layer, as T1-T2 dual-mode CAs. The relaxation performance of Fe/Mn multilayer NW was studied at 1.5 T. Results show that, when the length of the Fe layer is about 10 nm and the Mn is about 5 nm, the r1 value (21.8 mM-1s-1) and r2 value (74.8 mM-1s-1) of the Fe/Mn multilayer NW are higher than that of Mn NW (3.7 mM-1s-1) and Fe NW (59.3 mM-1s-1), respectively. We predict that our Fe/Mn multilayer NW could be used as T1-T2 dual mode MRI CAs in the near future.

10.
J Biomed Mater Res B Appl Biomater ; 109(4): 477-485, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32865333

RESUMO

To overcome the negative contrast limitations, and to improve the sensitivity of the magnetic resonance signals, the mesoporous silica coated Fe/Mn multilayered nanowires (NWs) were used as a T1 -T2 dual-mode contrast agents (CAs). The single component Fe and Mn NWs, and Fe/Mn multilayer NWs were synthesized by electrodeposition in the homemade anodic aluminum oxide (AAO) templates with the aperture of about 30 nm. The structural characterization and morphology of single component and multisegmented NWs was done by X-ray diffraction and transmission electron microscopy. The elemental composition of Fe/Mn multilayerd NWs was confirmed by energy-dispersive X-ray and energy-dispersive spectrometer. Vibrating sample magnetometer was used to test the magnetic properties, and 1.5 T magnetic resonance imaging (MRI) scanner was used to measure the relaxation efficiency. Importantly, the MRI study indicated that the Fe/Mn multilayer NWs showed a significant T1 -T2 imaging effect, and have longitudinal relaxivity (r1 ) value, that is, 1.25 ± 0.0329 × 10-4 µM-1 s-1 and transverse relaxivity (r2 ), that is, 5.13 ± 0.123 × 10-4 µM-1 s-1 , which was two times of r1 value (0.654 ± 0.00899 × 10-4 µM-1 s-1 ) of Mn NWs, and r2 value (2.96 ± 0.0415 × 10-4 µM-1 s-1 ) of Fe NWs. Hence, Fe/Mn multilayer NWs have potential to be used as T1 -T2 dual-mode CAs.


Assuntos
Meios de Contraste/análise , Imageamento por Ressonância Magnética/métodos , Nanofios/análise , Óxido de Alumínio , Materiais Revestidos Biocompatíveis , Meios de Contraste/química , Eletroquímica , Ferro , Manganês , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanofios/química , Porosidade , Dióxido de Silício , Difração de Raios X
11.
J Ethnopharmacol ; 281: 113548, 2021 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-33152427

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Huangkui capsule (HKC), extracted from Abelmoschus manihot (L.) medic (AM), as a patent proprietary Chinese medicine on the market for approximately 20 years, has been clinically used to treat chronic glomerulonephritis. Renal fibrosis has been implicated in the onset and development of diabetic nephropathy (DN). However, the potential application of HKC for preventing DN has not been evaluated. AIM OF THE STUDY: This study was designed to investigate the efficacy and underlying mechanisms of HKC combined with metformin (MET), the first-line medication for treating type 2 diabetes, in the treatment of renal interstitial fibrosis. MATERIALS AND METHODS: A rat model of diabetes-associated renal fibrosis was established by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg) combined with a high-fat and high-glucose diet. The rats were randomly divided into five groups: normal control, DN, HKC (1.0 g/kg/day), MET (100 mg/kg/d), and HKC plus MET (1.0 g/kg/day + 100 mg/kg/d). Following drug administration for 8 weeks, we collected blood, urine, and kidney tissue for analysis. Biochemical markers and metabolic parameters were detected using commercial kits. Histopathological staining was performed to monitor morphological changes in the rat kidney. High-glucose-induced human kidney HK-2 cells were used to evaluate the renal protective effects of HKC combined with MET (100 µg/mL+10 mmol/L). MTT assay and acridine orange/ethidium bromide were used to examine cell proliferation inhibition rates and apoptosis. Immunofluorescence assay and Western blot analysis were performed to detect renal fibrosis-related proteins including Klotho, TGF-ß1, and phosphorylated (p)-p38. RESULTS: Combination therapy (HKC plus MET) significantly improved the weight, reduced blood glucose (BG), blood urea nitrogen (BUN), total cholesterol (T-CHO), triglycerides (TG), low-density lipoprotein (LDL) and increased the level of high-density lipoprotein (HDL) of DN rats. Combination therapy also significantly reduced urine serum creatinine (SCR) and urine protein (UP) levels as well as reduced the degrees of renal tubule damage and glomerulopathy in DN rats. Combination therapy ameliorated renal fibrosis, as evidenced by reduced levels of alpha-smooth muscle actin and fibronectin and increased expression of E-cadherin in the kidneys. Moreover, HKC plus MET alleviated the degree of DN in part via the Klotho/TGF-ß1/p38MAPK signaling pathway. In vitro experiments showed that combination therapy significantly inhibited cell proliferation and apoptosis and regulated fibrosis-related proteins in high-glucose (HG)-induced HK-2 cells. Further studies revealed that combination therapy suppressed cell proliferation and fibrosis by inhibiting the Klotho-dependent TGF-ß1/p38MAPK pathway. CONCLUSIONS: HKC plus MET in combination suppressed abnormal renal cell proliferation and fibrosis by inhibiting the Klotho-dependent TGF-ß1/p38MAPK pathway. Collectively, HKC combined with MET effectively improved DN by inhibiting renal fibrosis-associated proteins and blocking the Klotho/TGF-ß1/p38MAPK signaling pathway. These findings improve the understanding of the pathogenesis of diabetes-associated complications and support that HKC plus MET combination therapy is a promising strategy for preventing DN.


Assuntos
Nefropatias Diabéticas/induzido quimicamente , Nefropatias Diabéticas/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Proteínas Klotho/metabolismo , Metformina/farmacologia , Fator de Crescimento Transformador beta1/metabolismo , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus Experimental , Dieta Hiperlipídica/efeitos adversos , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/administração & dosagem , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/administração & dosagem , Glucose/efeitos adversos , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/farmacologia , Proteínas Klotho/genética , Masculino , Metformina/administração & dosagem , Fitoterapia , Ratos , Ratos Sprague-Dawley , Fator de Crescimento Transformador beta1/genética , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
12.
Nanotechnology ; 31(48)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33118523

RESUMO

Carbon dots (CDs) are emerging as an ideal multifunctional materials due to their ease of preparation and excellent properties in medical imaging technology, environmental monitoring, chemical analysis and other fields. N-doped CDs modified with the epithelial cell adhesion molecule antibody (anti-EpCAM-NCDs) were synthesized in an ingenious and high-output approach. Due to the fluorescence enhancement effect of the introduced N atoms, the obtained anti-EpCAM-NCDs exhibited a strong green emission with an absolute quantum yield of up to 32.5%. Anti-EpCAM-NCDs have immunofluorescent properties and an active targeting function. The fluorescence effect and fluorescence quenching of anti-EpCAM-NCDs are used to image cells and detect Al3+, respectively. Experimental results show that this probe exhibited a wide linear response to Al3+over a concentration range of 0-100µM with a detection limit and quantification limit of 3 nM and 6 nM, respectively. Significantly, anti-EpCAM-NCDs, which have negligible cytotoxicity, excellent biocompatibility and high photostability, could be used for the intracellular imaging of HepG2 cells and the detection of Al3+in environmental and biological samples. As an efficient multifunctional material, anti-EpCAM-NCDs hold great promise for a number of applications in biological systems.


Assuntos
Alumínio/análise , Anticorpos/administração & dosagem , Carbono/química , Molécula de Adesão da Célula Epitelial/imunologia , Animais , Anticorpos/química , Anticorpos/farmacologia , Feminino , Células HeLa , Células Hep G2 , Humanos , Camundongos , Pontos Quânticos , Espectrometria de Fluorescência
13.
Appl Opt ; 59(24): 7371-7375, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32902505

RESUMO

Modeling the mechanical stress birefringence and slow-axis distributions of optical plates is critical for optical lithography systems. In this paper, the distributions of mechanical stress birefringence and the slow axes of optical plates were modeled by the finite element (FE) model, stress optic relations, and the ray-traced Jones matrices method. To validate this model, the load incremental approach was utilized to reduce the disturbance of residual birefringence in mechanical stress birefringence measurement. The measured distributions of birefringence and the slow axis of the optical plate show a good agreement with our numerical simulation results. This model provides a better understanding of simulation of mechanical stress birefringence and provides a reference for optical design and polarization analysis of other optical elements.

14.
Nanotechnology ; 31(43): 433001, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-32610303

RESUMO

Magnetic nanostructures and nanomaterials play essential roles in modern bio medicine and technology. Proper surface functionalization of nanoparticles (NPs) allows the selective bonding thus application of magnetic forces to a vast range of cellular structures and biomolecules. However, the spherical geometry of NPs poises a series of limitations in various potential applications. Mostly, typical spherical core shell structure consists of magnetic and non-magnetic layers have little tunability in terms of magnetic responses, and their single surface functionality also limits chemical activity and selectivity. In comparison to spherical NPs, nanowires (NWs) possess more degrees of freedom in achieving magnetic and surface chemical tenability. In addition to adjustment of magnetic anisotropy and inter-layer interactions, another important feature of NWs is their ability to combine different components along their length, which can result in diverse bio-magnetic applications. Magnetic NWs have become the candidate material for biomedical applications owing to their high magnetization, cheapness and cost effective synthesis. With large magnetic moment, anisotropy, biocompatibility and low toxicity, magnetic NWs have been recently used in living cell manipulation, magnetic cell separation and magnetic hyperthermia. In this review, the basic concepts of magnetic characteristics of nanoscale objects and the influences of aspect ratio, composition and diameter on magnetic properties of NWs are addressed. Some underpinning physical principles of magnetic hyperthermia (MH), magnetic resonance imaging (MRI) and magnetic separation (MS) have been discussed. Finally, recent studies on magnetic NWs for the applications in MH, MRI and MS were discussed in detail.


Assuntos
Hipertermia Induzida/métodos , Imageamento por Ressonância Magnética/métodos , Imãs/análise , Nanotecnologia/métodos , Nanofios/análise , Animais , Meios de Contraste/análise , Desenho de Equipamento , Humanos , Hipertermia Induzida/instrumentação , Imageamento por Ressonância Magnética/instrumentação , Magnetismo/instrumentação , Magnetismo/métodos , Nanotecnologia/instrumentação , Nanofios/ultraestrutura
15.
Materials (Basel) ; 12(23)2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31779229

RESUMO

In the last couple of decades, there has been a lot of progress in the synthesis methods of nano-structural materials, but still the field has a large number of puzzles to solve. Metal nanowires (NWs) and their alloys represent a sub category of the 1-D nano-materials and there is a large effort to study the microstructural, physical and chemical properties to use them for further industrial applications. Due to technical limitations of single component NWs, the hetero-structured materials gained attention recently. Among them, multi-segmented NWs are more diverse in applications, consisting of two or more segments that can perform multiple function at a time, which confer their unique properties. Recent advancement in characterization techniques has opened up new opportunities for understanding the physical properties of multi-segmented structures of 1-D nanomaterials. Since the multi-segmented NWs needs a reliable response from an external filed, numerous studies have been done on the synthesis of multi-segmented NWs to precisely control the physical properties of multi-segmented NWs. This paper highlights the electrochemical synthesis and physical properties of multi-segmented NWs, with a focus on the mechanical and magnetic properties by explaining the shape, microstructure, and composition of NWs.

16.
Plant Physiol ; 179(1): 143-155, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30381318

RESUMO

Most known plant viruses are spread from plant to plant by insect vectors. There is strong evidence that nonpersistently transmitted viruses manipulate the release of plant volatiles to attract insect vectors, thereby promoting virus spread. The mechanisms whereby aphid settling and feeding is altered on plants infected with these viruses, however, are unclear. Here we employed loss-of-function mutations in cucumber mosaic virus (CMV) and one of its host plants, tobacco (Nicotiana tabacum), to elucidate such mechanisms. We show that, relative to a CMVΔ2b strain with a deletion of the viral suppressor of RNAi 2b protein in CMV, plants infected with wild-type CMV produce higher concentrations of the reactive oxygen species (ROS) H2O2 in plant tissues. Aphids on wild-type CMV-infected plants engage in shorter probes, less phloem feeding, and exhibit other changes, as detected by electrical penetration graphing technology, relative to CMVΔ2b-infected plants. Therefore, the frequency of virus acquisition and the virus load per aphid were greater on CMV-infected plants than on CMVΔ2b-infected plants. Aphids also moved away from initial feeding sites more frequently on wild-type CMV infected versus CMVΔ2b-infected plants. The role of H2O2 in eliciting these effects on aphids was corroborated using healthy plants infused with H2O2 Finally, H2O2 levels were not elevated, and aphid behavior was unchanged, on CMV-infected RbohD-silenced tobacco plants, which are deficient in the induction of ROS production. These results suggest that CMV uses its viral suppressor of RNAi protein to increase plant ROS levels, thereby enhancing its acquisition and transmission by vector insects.


Assuntos
Afídeos/virologia , Cucumovirus/fisiologia , Insetos Vetores/virologia , Doenças das Plantas/virologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Cucumovirus/genética , Transmissão de Doença Infecciosa , Peróxido de Hidrogênio/metabolismo , Interferência de RNA
17.
J Exp Bot ; 68(21-22): 5923-5935, 2017 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-29140446

RESUMO

Previous research has shown that elevated CO2 reduces plant resistance against insects and enhances the water use efficiency of C3 plants, which improves the feeding efficiency of aphids. Although plant mitogen-activated protein kinases (MAPKs) are known to regulate water relations and phytohormone-mediated resistance, little is known about the effect of elevated CO2 on MAPKs and the cascading effects on aphids. By using stably transformed Nicotiana attenuata plants silenced in MPK4, wound-induced protein kinase (WIPK), or salicylic acid-induced protein kinase (SIPK), we determined the functions of MAPKs in plant-aphid interactions and their responses to elevated CO2. The results showed that among all plant genotypes, inverted repeat MPK4 plants had the largest stomatal apertures, the lowest water content, the strongest jasmonic acid (JA)-dependent resistance, and the lowest aphid numbers, suggesting that MPK4 affects plant responses to aphids by regulating stomatal aperture and JA-dependent resistance. Regardless of aphid infestation, elevated CO2 up-regulated MPK4, but not WIPK or SIPK, in wild-type plants. Elevated CO2 increased the number, mean relative growth rate, and feeding efficiency of aphids on all plant genotypes except inverted repeat MPK4. We conclude that MPK4 is a CO2-responsive plant determinant that regulates the molecular interaction between plants and aphids.


Assuntos
Afídeos/fisiologia , Dióxido de Carbono/análise , Cadeia Alimentar , Proteínas Quinases Ativadas por Mitógeno/genética , Nicotiana/fisiologia , Proteínas de Plantas/genética , Regulação para Cima , Animais , Comportamento Alimentar , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas de Plantas/metabolismo
18.
Appl Opt ; 56(28): 7898-7904, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29047776

RESUMO

A setup for surface-plasmon-resonance- (SPR) based imaging ellipsometry was developed, which gains from the sensitivities of both SPR and ellipsometry to ultrathin film parameters. It is based on Otto's configuration for prism-sample coupling and a wide-beam imaging ellipsometry. A set of ultrathin gold and silver films was measured to determine their optical constants and thicknesses. Coupling the sample using a prism with a convex surface enables us to capture images of generated SPR elliptical fringes, which correspond to different SPR amplitude values at different air gap thicknesses. Analysis of the images acquired at different polarizer and analyzer angles provides the ellipsometric functions Ψ and Δ versus thickness of air gap and hence the extraction of the optical constants of ultrathin metal films. The measured film thickness is in agreement with the results of x-ray reflectivity measurements.

19.
Int J Biol Macromol ; 104(Pt A): 900-908, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28666830

RESUMO

In the present study, effect of Sophora subprosrate polysaccharide on PCV2 infection-induced inflammation and histone acetylation modification in swine alveolar macrophage 3D4/2 cells was described for the first time. The relationship between histone acetylation modifications and inflammation response was investigated. The results showed that PCV2 infection induced inflammation by promoting the secretion of TNF-α, IL-1ß, IL-6 and IL-10 in 3D4/2 cells. The production of TNF-α, IL-1ß and IL-6 and their mRNA expression levels markedly decreased while the level and mRNA expression of IL-10 were elevated when the cells were treated with Sophora subprosrate polysaccharide. The SSP also decreased the activity of HATs, histone H3 acetylation (Ac-H3) and histone H4 acetylation (Ac-H4), p65 phosphorylation (P-p65) in the cells infected with PCV2 while HDACs activity was down-regulated, which involved in the inhibitory effect of SSP on histone acetylation and NF-κB signaling pathways activation. Down-regulation of HAT1 mRNA expression and up-regulation of HDAC1 mRNA expression further support the inhibitory effect of SSP on histone acetylation. In conclusion, Sophora subprosrate polysaccharide antagonized inflammatory responses induced by PCV2, via mechanisms involved in histone acetylation and NF-κB signaling pathways.


Assuntos
Quimiocinas/metabolismo , Circovirus/fisiologia , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/virologia , NF-kappa B/metabolismo , Polissacarídeos/farmacologia , Sophora/química , Acetilação/efeitos dos fármacos , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Histona Acetiltransferases/metabolismo , Histona Desacetilases/metabolismo , Macrófagos Alveolares/citologia , Macrófagos Alveolares/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Suínos
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