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1.
New Microbiol ; 43(1): 38-40, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32334490

RESUMO

Silicon nanowires (SiNWs) are attractive functional nanomaterials for biomedical applications. The ability to easily tune their size and density, potential biocompatibility, and knowledge of the chemical activation of SiNWs surface make them natural tools to interact with biological materials. We evaluated the possibility of exploiting SiNWs as carriers to introduce organic compounds into cells. The cellular toxicity and the internalization capacity of free-standing and label-free SiNWs were tested on Buffalo Green Monkey cells (BGM). Confocal fluorescent observation of SiNWs conjugated with fluorescein-polyethylene imine (PEI) confirmed the internalization of the NWs into the Buffalo Green Monkey Cells (BGM).


Assuntos
Células , Nanofios , Silício , Internalização do Vírus , Animais , Linhagem Celular , Células/efeitos dos fármacos , Células/virologia , Chlorocebus aethiops , Nanofios/toxicidade , Nanofios/virologia , Silício/metabolismo , Silício/toxicidade , Vírus/metabolismo
2.
Nature ; 580(7802): 188-189, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32269348
3.
Nature ; 579(7798): 205-209, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32161384

RESUMO

Nuclear spins are highly coherent quantum objects. In large ensembles, their control and detection via magnetic resonance is widely exploited, for example, in chemistry, medicine, materials science and mining. Nuclear spins also featured in early proposals for solid-state quantum computers1 and demonstrations of quantum search2 and factoring3 algorithms. Scaling up such concepts requires controlling individual nuclei, which can be detected when coupled to an electron4-6. However, the need to address the nuclei via oscillating magnetic fields complicates their integration in multi-spin nanoscale devices, because the field cannot be localized or screened. Control via electric fields would resolve this problem, but previous methods7-9 relied on transducing electric signals into magnetic fields via the electron-nuclear hyperfine interaction, which severely affects nuclear coherence. Here we demonstrate the coherent quantum control of a single 123Sb (spin-7/2) nucleus using localized electric fields produced within a silicon nanoelectronic device. The method exploits an idea proposed in 196110 but not previously realized experimentally with a single nucleus. Our results are quantitatively supported by a microscopic theoretical model that reveals how the purely electrical modulation of the nuclear electric quadrupole interaction results in coherent nuclear spin transitions that are uniquely addressable owing to lattice strain. The spin dephasing time, 0.1 seconds, is orders of magnitude longer than those obtained by methods that require a coupled electron spin to achieve electrical driving. These results show that high-spin quadrupolar nuclei could be deployed as chaotic models, strain sensors and hybrid spin-mechanical quantum systems using all-electrical controls. Integrating electrically controllable nuclei with quantum dots11,12 could pave the way to scalable, nuclear- and electron-spin-based quantum computers in silicon that operate without the need for oscillating magnetic fields.


Assuntos
Modelos Teóricos , Silício/química , Fenômenos Eletromagnéticos , Elétrons , Pontos Quânticos/química
4.
Nat Biomed Eng ; 4(2): 223-231, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32051578

RESUMO

The use of nanophotonics to rapidly and precisely reconfigure light beams for the optical stimulation of neurons in vivo has remained elusive. Here we report the design and fabrication of an implantable silicon-based probe that can switch and route multiple optical beams to stimulate identified sets of neurons across cortical layers and simultaneously record the produced spike patterns. Each switch in the device consists of a silicon nitride waveguide structure that can be rapidly (<20 µs) reconfigured by electrically tuning the phase of light. By using an eight-beam probe, we show in anaesthetized mice that small groups of single neurons can be independently stimulated to produce multineuron spike patterns at sub-millisecond precision. We also show that a probe integrating co-fabricated electrical recording sites can simultaneously optically stimulate and electrically measure deep-brain neural activity. The technology is scalable, and it allows for beam focusing and steering and for structured illumination via beam shaping. The high-bandwidth optical-stimulation capacity of the device might facilitate the probing of the spatiotemporal neural codes underlying behaviour.


Assuntos
Estimulação Encefálica Profunda/instrumentação , Estimulação Encefálica Profunda/métodos , Hipocampo/fisiologia , Nanotecnologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Potenciais de Ação , Animais , Desenho de Equipamento , Feminino , Camundongos Transgênicos , Processamento de Sinais Assistido por Computador , Silício
5.
Sci Total Environ ; 715: 136846, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32040993

RESUMO

The use of exogenous silicon (Si) amendments, such as Si fertilizers and biochar, can effectively increase crop Si uptake and the formation of phytoliths, which are siliceous substances that are abundant in numerous plant species. Phytolith-occluded carbon (C) (PhytOC) accumulation in soil plays an important role in long-term soil organic C (SOC) storage. Nevertheless, the effects of both Si fertilizer and biochar application on PhytOC sequestration in forest plant-soil systems have not been studied. We investigated the impact of Si fertilizer and biochar applications on 1) the PhytOC pool size, the solubility of plant and soil phytoliths, and soil PhytOC in soil physical fractions (light (LFOM) and heavy fractions of organic matter (HFOM)) in Moso bamboo (Phyllostachys pubescens) forests; and 2) the relationships among plant and soil PhytOC concentrations and soil properties. We used a factorial design with three Si fertilizer application rates: 0 (S0), 225 (S1) and 450 (S2) kg Si ha-1, and two biochar application rates: 0 (B0) and 10 (B1) t ha-1. The concentrations of PhytOC in the bamboo plants and topsoil (0-10 cm) increased with increasing Si fertilizer addition, regardless of biochar application. Biochar addition increased the soil PhytOC pool size, as well as the LFOM- and HFOM-PhytOC fractions, regardless of Si fertilizer application. The Si fertilizer application increased or had no effect on soil phytolith solubility with or without biochar application, respectively. Soil PhytOC was correlated with the concentration of soil organic nitrogen (R2 = 0.32), SOC (R2 = 0.51), pH (R2 = 0.28), and available Si (R2 = 0.23). Furthermore, Si fertilizer application increased plant and soil PhytOC by increasing soil available Si. Moreover, biochar application increased soil PhytOC concentration in LFOM-PhytOC and the unstable fraction of PhytOC. We conclude that Si fertilizer and biochar application promoted PhytOC sequestration in the plant-soil system and changed its distribution in physical fractions in the Moso bamboo plantation in subtropical China.


Assuntos
Fertilizantes , Carbono , Carvão Vegetal , China , Silício , Solo
6.
PLoS One ; 15(1): e0227232, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923253

RESUMO

Additive manufactured, porous bone implants have the potential to improve osseointegration and reduce failure rates of orthopaedic devices. Substantially porous implants are increasingly used in a number of orthopaedic applications. HA plasma spraying-a line of sight process-cannot coat the inner surfaces of substantially porous structures, whereas electrochemical deposition of calcium phosphate can fully coat the inner surfaces of porous implants for improved bioactivity, but the osseous response of different types of hydroxyapatite (HA) coatings with ionic substitutions has not been evaluated for implants in the same in vivo model. In this study, laser sintered Ti6Al4V implants with pore sizes of Ø 700 µm and Ø 1500 µm were electrochemically coated with HA, silicon-substituted HA (SiHA), and strontium-substituted HA (SrHA), and implanted in ovine femoral condylar defects. Implants were retrieved after 6 weeks and histological and histomorphometric evaluation were compared to electrochemically coated implants with uncoated and HA plasma sprayed controls. The HA, SiHA and SrHA coatings had Ca:P, Ca:(P+Si) and (Ca+Sr):P ratios of 1.53, 1.14 and 1.32 respectively. Electrochemically coated implants significantly promoted bone attachment to the implant surfaces of the inner pores and displayed improved osseointegration compared to uncoated scaffolds for both pore sizes (p<0.001), whereas bone ingrowth was restricted to the surface for HA plasma coated or uncoated implants. Electrochemically coated HA implants achieved the highest osseointegration, followed by SrHA coated implants, and both coatings exhibited significantly more bone growth than plasma sprayed groups (p≤0.01 for all 4 cases). SiHA had significantly more osseointegration when compared against the uncoated control, but no significant difference compared with other coatings. There was no significant difference in ingrowth or osseointegration between pore sizes, and the bone-implant-contact was significantly higher in the electrochemical HA than in SiHA or SrHA. These results suggest that osseointegration is insensitive to pore size, whereas surface modification through the presence of an osteoconductive coating plays an important role in improving osseointegration, which may be critically important for extensively porous implants.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/farmacologia , Implantes Experimentais , Osseointegração/efeitos dos fármacos , Porosidade , Silício/farmacologia , Estrôncio/farmacologia , Animais , Fêmur/patologia , Lasers , Teste de Materiais/métodos , Equipamentos Ortopédicos , Osseointegração/fisiologia , Ovinos , Propriedades de Superfície , Titânio/farmacologia
7.
Nature ; 577(7790): 320-321, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31942058
8.
Chem Commun (Camb) ; 56(16): 2455-2458, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31996872

RESUMO

A group of asymmetric Si-rhodamine scaffolds was designed for protease-activated NIR probes. Dual pH-inertia for both spirocyclized fluorescent probes and fluorescent products of zwitterions form over a wide range of pH (4.0-11.0). Leucine aminopeptidase (LAP) and γ-glutamyl transpeptidase (GGT) were monitored by fluorescent imaging in vivo.


Assuntos
Corantes Fluorescentes/química , Imagem Óptica , Peptídeo Hidrolases/análise , Rodaminas/química , Silício/química , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/metabolismo , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Raios Infravermelhos , Estrutura Molecular , Peptídeo Hidrolases/metabolismo , Rodaminas/metabolismo , Silício/metabolismo , Espectrometria de Fluorescência
9.
Sci Total Environ ; 712: 136497, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-31945526

RESUMO

Direct discharge of untreated industrial waste water in water bodies and then irrigation from these sources has increased trace metals contamination in paddy fields of southern China. Among trace metals, cadmium (Cd) and lead (Pb) are classified as most harmful contaminants in farmland to many organisms including plants, animals and humans. Rice is a staple food which is consumed by half population of the world; due to longer growth period it can easily absorb and accumulate the trace metals from soil. The objective of study was to check the efficacy of Se and Si NPs (nanoparticles) alone or in combination on metals accumulation and Se-fortified rice (Oryzasativa L.) production as their efficiency remained untested. Alone as well as combined application of Se- and Si-NPs (5, 10 and 20 mg L-1) was achieved along with CK. All the treatments significantly reduced the Cd and Pb contents in brown rice, except CK, Se3, Si1 and Se1Si3. Combined application of Se and Si (Se3Si2) was more effective in reducing the Cd and Pb contents by 62 and 52%, respectively. In addition, foliar application of both NPs improved the rice growth and quality by increasing the grain yield, rice biomass, and Se contents in brown rice. Highest concentration of Se (1.35 mg kg-1) in brown rice was observed with combined application of Se- and Si-Nps (Se3Si2). Selenium speciation revealed the presence of organic species (74%) in brown rice. The combinations of different doses of Se- and Si-Nps are the main determining factor for total concentration of metals in grains. These results demonstrate that foliage supplementation of Se and Si-Nps alleviate the Cd and Pb toxicity by reducing the metals' concentration in brown rice. Additionally foliage supplementation improved the nutritional quality by reducing the phytic acid contents in rice grains.


Assuntos
Nanopartículas , Oryza , Cádmio , China , Chumbo , Selênio , Silício , Solo , Poluentes do Solo
10.
Plant Biol (Stuttg) ; 22(3): 472-479, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31990448

RESUMO

Cadmium (Cd) is detrimental to crops and the environment. This work examines the natural mechanisms underlying silicon- (Si-)directed Cd detoxification in rice plants. The addition of Si to plants under Cd stress caused significant improvements in morphological parameters, chlorophyll score, Fv /Fm and total soluble protein concentration compared to controls, confirming that Si is able to ameliorate Cd-induced damage in rice plants. This morpho-physiological evidence was correlated with decreased cell death and electrolyte leakage after Si application. The results showed no critical changes in root Cd concentration, while shoot Cd decreased significantly after Si supplementation in comparison with Cd-stressed rice. Additionally, expression of Cd transporters (OsNRAMP5 and OsHMA2) was significantly down-regulated while the concentration of phytochelatin, cysteine and glutathione, together with expression of OsPCS1 (phytochelatin synthase) in roots of Cd-stressed rice was significantly induced when subjected to Si treatment. This confirms that the alleviation of Cd stress is not only limited to the down-regulation of Cd transporters but also closely related to the phytochelatin-driven vacuolar storage of Cd in rice roots. The enzymatic analysis further revealed the role of SOD and GR enzymes in protecting rice plants from Cd-induced oxidative harm. These findings suggest a mechanistic basis in rice plants for Si-mediated mitigation of Cd stress.


Assuntos
Cádmio , Depuradores de Radicais Livres , Oryza , Fitoquelatinas , Silício , Cádmio/metabolismo , Depuradores de Radicais Livres/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Oryza/química , Oryza/efeitos dos fármacos , Fitoquelatinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Silício/metabolismo , Silício/farmacologia
11.
Sci Total Environ ; 704: 135461, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31810680

RESUMO

Stable carbon isotope ratios (δ13C) are widely used as climate proxies for assessing and predicting climatic information at an annual resolution. However, the detailed information in the isotopes that results from intra-annual climate scenarios and is associated with mineral accumulation remains unclear. Combined with investigations of elements and ash contents, variations in foliar δ13C in relation to annual, winter and summer climate scenarios were investigated in a dendroclimatologically important tree species Sabina przewalskii Kom. Foliar δ13C exhibited a significant negative correlation with mean annual temperature, mean annual precipitation and mean annual relative humidity as well as significant positive correlations with elevation. Climatic factors in winter and summer have opposite effects on the variation of δ13C. The beneficial mineral element Si had a significant positive correlation with foliar δ13C, whereas the essential mineral elements K, Ca, and Mg did not. Specifically, Si and δ13C have similar correlations with climate factors and elevation. These results suggest that measurement of Si content has a similar potential to δ13C for use as an alternative climate indicator when detailed climatic information may otherwise be limited and provide a basis for understanding the integration of δ13C in plant responses to climate.


Assuntos
Clima , Monitoramento Ambiental , Silício/análise , Isótopos de Carbono/análise , Folhas de Planta/química , Tibet , Árvores
12.
Chemosphere ; 242: 125128, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31678846

RESUMO

Many reports suggest that exogenous Si addition could reduce Cd translocation to aerial part and make grain safe for rice production. But it remains unclear whether its supplementation during different growth phases can differentially impact Cd uptake in rice. Here, Positive effects of Si applied at different growth phases on biomass and yield of rice were observed. Dry weight of shoot including stem, leaf and grain was enhanced significantly by 15% when Si added at transplanting stage. Grain-yields supplied with Si at transplanting, jointing and heading stages were increased obviously by 14%, 11% and 12%, respectively. Higher percentage of filled spikelet and lower unfilled spikelet number per panicle were found when Si supplied at jointing stage. The increases of Cd accumulation in rice plants by Si application were mainly manifested in roots. Compared to CK, Cd accumulation in root when Si applied at transplanting and tillering stages were elevated by 75% and 64%, respectively. While Cd accumulation in aboveground tissues were all declined by Si addition. Bioconcentration and translocation factors were decreased significantly when Si added at jointing stage. In addition, higher soil pH, lowest available Cd-concentration in soil and Cd2+ concentration in xylem sap at 15d after flowering were found when the Si was applied at jointing stage. Overall, Si application at transplanting would be more beneficial to the growth of rice and increased Cd content in root, while Si supplied at jointing would be more favorable for grain filling and reducing Cd accumulation in shoot.


Assuntos
Cádmio/metabolismo , Oryza/metabolismo , Silício , Poluentes do Solo/metabolismo , Biomassa , Cádmio/análise , Grão Comestível/química , Poluição Ambiental , Oryza/química , Folhas de Planta/química , Solo/química , Poluentes do Solo/análise
13.
Anal Bioanal Chem ; 412(2): 279-288, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31734712

RESUMO

Echinococcosis is a serious zoonotic parasitic disease that could be fatal without diagnosis and treatment in a timely manner. Herein, we present a rapid and label-free method for screening of echinococcosis using surface-enhanced Raman spectroscopy (SERS). Three groups of serum SERS spectra based on porous silicon/silver composites are obtained: one group from healthy volunteers (normal, n = 163) and two other groups from patients with pathologically confirmed echinococcosis (cystic echinococcosis (CE), n = 69 and alveolar echinococcosis (AE), n = 38). The derived characteristic spectrum was analyzed to explain differences between echinococcosis and healthy volunteers and a principal component analysis (PCA) was applied for classification. Raman spectra revealed that high sensitivity and specificity for echinococcosis diagnosis were associated with the contents of phenylalanine and tyrosine. In addition, Raman spectroscopy analysis identified two metabolites including phenylalanine and carotenoids that could distinguish three types of serum. Orthogonal partial least squares discriminant analysis (OPLS-DA) was successfully used as a discriminative model to classify echinococcosis with the highest sensitivity and specificity of 100% and 98.6%, respectively. Combination of serum metabolomics with SERS enabled accurate screening of echinococcosis patients. The results indicate that SERS-based serum profile analysis has the potential to be a valuable tool for the early diagnosis and screening of echinococcosis.


Assuntos
Equinococose/sangue , Análise Espectral Raman/métodos , Estudos de Casos e Controles , Humanos , Silício/química , Prata/química
14.
J Sci Food Agric ; 100(4): 1547-1557, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31769027

RESUMO

BACKGROUND: It is important to increase productivity and improve plant quality at the same time as preserving the principles of safety and productivity. The present study aimed to evaluate the effects of different concentrations of sodium metasilicate and calcium chloride, applied as fertilizers, on the productivity and phytochemical characteristics of Sauvignon Blanc grapes and their respective wines. RESULTS: The experiments were conducted using 2017 and 2018 vintages of commercial Sauvignon Blanc grapes. The treatments consisted of applying separately different concentrations of sodium metasilicate (0, 4, 8 and 12 g L-1 ) or calcium chloride (0, 5, 10 and 15 g L-1 ). The treatments were carried out during four phenological phases. The grapes were harvested at technical maturity and white wines were elaborated. The application of inorganic salts, silicon and calcium to the grapes had a significant effect on the vineyard productivity. The best results were obtained with 4 and 8 g L-1 silicon and 15 g L-1 calcium. An increase in the concentration of phenolics in the grapes was noted. These compounds have antioxidant capacity, which is one of the factors responsible for the resistance of the grapes to pathogens. CONCLUSION: The application of 4 and 8 g L-1 silicon and 15 g L-1 calcium to the grapes represents a potential alternative fertilizing strategy, which could increase the plant yield without damaging the phytochemical characteristics of the fruit and its derivatives. © 2020 Society of Chemical Industry.


Assuntos
Cálcio/metabolismo , Produção Agrícola/métodos , Frutas/química , Compostos Fitoquímicos/química , Silício/metabolismo , Vitis/metabolismo , Vinho/análise , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Compostos Fitoquímicos/metabolismo , Vitis/química , Vitis/crescimento & desenvolvimento
15.
Sci Total Environ ; 704: 135252, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31831228

RESUMO

Novel salt-based biochar was prepared by loading silicon (Si) on cornstalk biomass with "one-step sintering" technique. Manganese (Mn) was also used to modify biochar with the same method as a control. Surface morphology, elemental composition, crystal structure and surface area of "salt-based biochars" were analyzed by SEM + EDS, XRD, FTIR and BET, and the effects of the dosage of absorbent and pH of solution on the adsorption process were explored. Si and Mn could be successfully attached on the biochar surface as oxide forms. SiBC exhibited a dense and agglomerated surface, while MnBC was a kind of porous and rough materials. The optimal adsorption capability would realize when putting 2 g/L of biochar composites at pH = 5-6. Adsorption isotherms, adsorption kinetics, combine with FTIR and XPS were carried out to help to elaborate the adsorption mechanisms. The maximum adsorption capacity of Cu (II) was 152.61 mg/g on SiBC and it could reach at 97% of removal rate within 10 min when the concentration was 100 mg/L, while MnBC had to take 500 min to achieve the same adsorption effect, and reached 187.76 mg/g of maximum adsorption capacity. Langmuir model and pseudo-second-order model were more suitable for both SiBC and MnBC, which meant the monolayer and chemical adsorption were dominated. Surface complexation and precipitation was attributed to SiBC. Specialistic adsorption, ion exchange and intra-particle diffusion was put it down to MnBC.


Assuntos
Cobre/química , Modelos Químicos , Silício/química , Adsorção , Biomassa , Carvão Vegetal , Concentração de Íons de Hidrogênio , Íons , Cinética , Manganês , Óxidos
16.
Sci Total Environ ; 704: 135239, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31822424

RESUMO

Addition of Si to soil can reduce As uptake and accumulation in rice, while also enhancing As release from soil particles via competing sorption sites in soil minerals with As. Foliar application of Si might be an alternative pathway to reduce As accumulation in rice. It is not clear which growing stage would be better for spraying different types of Si solution to reduce inorganic As in edible parts of rice. Soil pot experiments were conducted to investigate whether total As and inorganic As accumulation in rice grains was alleviated via spraying Si in As-contaminated paddy soil. The results showed that foliar Si application at the tillering or jointing stage significantly reduced As concentrations in rice husks and grain via inhibiting the translocation of As from straw to husk or grain compared with other growing stages. Spraying of Si at the tillering stage markedly decreased the concentrations of inorganic As in rice bran and polished rice, accounting for 27.3% and 61.4% respectively. Furthermore, spraying Si solution mixed with surfactant-Tween 80 not only dramatically reduced the total As in rice tissues by 48.8%, but also significantly alleviated the accumulation of inorganic As in rice grain by 49.2%. Spraying Si restricted inorganic As in rice grain through the mechanism by which foliar Si application at tillering stage increased the Si concentrations in shoot and root, which downregulated Si transporters of Lsi1 and Lsi2 in the root and Lsi6 in the blade and sheath significantly, and finally decreased As uptake and transport. Therefore, spraying Si is an alternative and efficient pathway to reduce inorganic As accumulation of rice grain in As-contaminated soil.


Assuntos
Agricultura/métodos , Arsênico/análise , Oryza/química , Silício/química , Poluentes do Solo/análise , Arsênico/química , Solo/química , Poluentes do Solo/química
17.
J Sci Food Agric ; 100(2): 732-743, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31597201

RESUMO

BACKGROUND: Using water with high salinity for plant fertigation may have detrimental effects on plant development and total yield and on the quality of the crop produced. As a possible means to alleviate the negative effects of salinity, silicon (Si) can be incorporated in the nutrient solution supplied to plants. In the present study, hydroponically grown tomato (Solanum lycopersicum Mill.) plants were subjected to two different salinity levels (0 and 50 mmol L-1 NaCl) with and without the application of Si (0 and 2 mmol L-1 K2 SiO3 ) in order to evaluate its possible positive impact on mitigation of salinity stress-induced symptoms. An additional experiment was implemented with postharvest Si application (sodium silicate) to investigate effects on the shelf-life of tomato fruit. RESULTS: Salinity (50 mmol L-1 NaCl) decreased plant size, total yield and fresh fruit weight while a high percentage of blossom end rot symptoms of tomato fruit was also observed. The application of Si in the nutrient solution counteracted these detrimental effects, generating a higher yield and healthier fruit (lower blossom end rot incidence) compared to the untreated plants (no application of Si). Salinity improved several quality-related traits in tomato fruit, resulting in higher marketability, whereas the addition of Si (pre- and postharvest) maintained fruit firmness following storage thereby increasing the shelf-life of tomato fruit. CONCLUSIONS: These findings indicate that Si application (pre- and postharvest) could provide an effective means of alleviating the unfavorable effects of using low-quality water in plant fertigation on tomato plant development, fruit yield and post-harvest quality, through increased fruit firmness. © 2019 Society of Chemical Industry.


Assuntos
Produção Agrícola/métodos , Frutas/química , Lycopersicon esculentum/efeitos dos fármacos , Silício/farmacologia , Cloreto de Sódio/farmacologia , Flores , Frutas/efeitos dos fármacos , Frutas/metabolismo , Hidroponia , Lycopersicon esculentum/química , Lycopersicon esculentum/metabolismo , Salinidade
18.
Ecotoxicol Environ Saf ; 188: 109885, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704322

RESUMO

We investigated the physio-molecular effects of separate and combined cadmium (Cd; 200 µM) and salinity (NaCl; 100 mM) stress on date palm during silicon (Si; 1.0 mM) applications. The results showed that exogenous Si led to significant improvements in plant growth, as well as physiology when compared with non-Si-treated seedling under stressed (Cd/NaCl) conditions. Interestingly, Si application led to lower metal (Cd) uptake and enhanced plant macronutrient uptake under combined stress, in turn, alleviating the combined salinity- and Cd-induced oxidative stress by lowering the lipid peroxidation rate, and peroxidase and catalase activities. Furthermore, ascorbate peroxidase level and the cytosolic Cu/Zn superoxide dismutase expression were significantly enhanced by Si application under combined stress. We further analyzed the effect of Si on modulation of stress-related hormonal crosstalk. Si markedly downregulated endogenous salicylic acid, jasmonic acid, and abscisic acid under NaCl stress and combined NaCl-Cd stress. However, during Cd toxicity alone, Si showed varying accumulation of these phytohormones. The results suggest that hindering the Cd uptake and enhancing silicon accumulation ultimately led to improvement of biomass and efficiency of the antioxidant system for alleviating combined stress. Moreover, higher transcript accumulation of PROLINE TRANSPORTER 2 and GAPDH and downregulation of ABA RECEPTOR by Si treatment under combined stress in date palm seedlings indicate the stress-ameliorative role of Si. The study provides evidence of the positive influence of Si on alleviating the combined toxicity of Cd and NaCl in date palm and can be further extended for field trials in Cd- and salinity-affected areas.


Assuntos
Cádmio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Phoeniceae/efeitos dos fármacos , Salinidade , Silício/farmacologia , Antioxidantes/metabolismo , Cádmio/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Phoeniceae/crescimento & desenvolvimento , Phoeniceae/metabolismo , Phoeniceae/fisiologia , Reguladores de Crescimento de Planta/genética , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Plântula/fisiologia , Silício/metabolismo
19.
Chemosphere ; 240: 124907, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550592

RESUMO

Deciphering the mechanism of Cd accumulation in crops is imperative for minimizing soil-to-plant transfer of Cd to improve safe food production. Hydroponic experiments were performed examining Cd accumulation, growth performance and protein characteristics of two rice genotypes, Xiushui817 and Zheda821, with low and high grain Cd accumulation, respectively, under Cd stress and in the presence of Si. Xiushui817 had lower root-to-shoot Cd translocation and was more sensitive to Cd stress than Zheda821. Si reduced the shoot Cd content in both genotypes but more efficacy in Zheda821. Tandem mass tags (TMT)-based proteomic analysis identified 25 proteins associated with low grain Cd accumulation, including vacuolar H+-pyrophosphatase 1 (OVP1) that was up-regulated after Si addition in Zheda821. The sequence comparison of OVP1 showed one nucleotide difference in Xiushui817 relative to Zheda821 resulting in one amino acid. Overexpression of OVP1 reduced shoot Cd concentration and improved the growth of rice compared with WT under both control and Cd treatment. The results highlight the significant roles of OVP1 in both Cd accumulation and the Si-induced Cd reduction in rice. Our findings provide valuable insights into the molecular mechanism of low Cd accumulation and Si-induced decrease in Cd accumulation in rice. OVP1 could be used for transgenic overexpression in rice or other cereals for safe food production.


Assuntos
Cádmio/farmacocinética , Oryza/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Pirofosfatases/metabolismo , Silício/farmacologia , Cádmio/toxicidade , Regulação da Expressão Gênica de Plantas , Genótipo , Hidroponia , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Proteômica/métodos , Pirofosfatases/genética , Poluentes do Solo/farmacocinética
20.
Waste Manag ; 103: 146-158, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31877498

RESUMO

The waste materials available as sources of silicon and aluminum for producing porous materials like amorphous silicas, aluminas, amorphous silica-aluminas, and zeolites, to be used as catalyst and adsorbents, are briefly summarized. The procedures for preparing these materials from wastes are also taken into account. The limits of this approach in terms of economy and environmental protection are also briefly considered. It is concluded that mesoporous materials can be prepared from wastes, but care to product quality and to overall process efficiency is needed.


Assuntos
Alumínio , Dióxido de Silício , Óxido de Alumínio , Catálise , Porosidade , Silício
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