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1.
Biol Res ; 54(1): 15, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33933166

RESUMO

BACKGROUND: Water stress is one of the serious abiotic stresses that negatively influences the growth, development and production of sugarcane in arid and semi-arid regions. However, silicon (Si) has been applied as an alleviation strategy subjected to environmental stresses. METHODS: In this experiment, Si was applied as soil irrigation in sugarcane plants to understand the mitigation effect of Si against harmful impact of water stress on photosynthetic leaf gas exchange. RESULTS: In the present study we primarily revealed the consequences of low soil moisture content, which affect overall plant performance of sugarcane significantly. Silicon application reduced the adverse effects of water stress by improving the net photosynthetic assimilation rate (Anet) 1.35-18.75%, stomatal conductance to water vapour (gs) 3.26-21.57% and rate of transpiration (E) 1.16-17.83%. The mathematical models developed from the proposed hypothesis explained the functional relationships between photosynthetic responses of Si application and water stress mitigation. CONCLUSIONS: Silicon application showed high ameliorative effects on photosynthetic responses of sugarcane to water stress and could be used for mitigating environmental stresses in other crops, too, in future.


Assuntos
Saccharum , Silício , Desidratação , Fotossíntese , Folhas de Planta , Água
2.
Plant Physiol Biochem ; 162: 752-761, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33799186

RESUMO

In this study, the role of nitric oxide (NO) burst in modulating Si-induced defensive responses in leaves and roots of Salvia officinalis under copper (Cu) stress were investigated. The result showed that 400 µM Cu markedly reduced shoot dry weight, but increased electrolyte leakage (EL) in leaves and both Si and sodium nitroprusside (SNP as the NO donor) improved these attributes in a dose-dependent manner. Interestingly, Cu toxicity systemically boosted a NO burst in both roots and shoots and applying Si and SNP markedly intensified it. The application of Si and SNP alone as well as their combination improved growth parameters and systemically alleviated Cu-induced lipid peroxidation and H2O2 accumulation through lowering Cu accumulation, increasing proline content, enhancing the activities of catalase (CAT) and superoxide dismutase (SOD) in both roots and leaves and up-regulating expression of SOD gene in leaves of S. officinalis. NO generation was substantially arrested and the responses induced by Si were significantly suppressed by pretreatment with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxy l-3-oxide (cPTIO) as a NO scavenger, Nx-Nitro- L-arginine methyl ester hydrochloride (L-NAME) as a nitric oxide synthase inhibitor, and tungstate as a nitrate reductase inhibitor. These novel results indicate that Si can induce Cu tolerance through triggering NO generation which systemically modulates defensive reactions in both roots and leaves of Salvia officinalis.


Assuntos
Óxido Nítrico , Salvia officinalis , Antioxidantes , Cobre/toxicidade , Peróxido de Hidrogênio , Nitroprussiato/farmacologia , Raízes de Plantas , Silício
3.
Int J Nanomedicine ; 16: 2501-2513, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33824588

RESUMO

Introduction: Aim to obtain a NO donor that can control released NO in vivo with the high efficacy of tumor suppression and targeting, a nanoplatform consisting of FA-Fe3O4@mSiO2-Au/DOX was constructed. Methods: In vitro, the nanoplatform catalyzed NO's release with the maximum value of 4.91 µM within 60 min at 43°C pH=5.0, which was increased by 1.14 times when the temperature was 37°C. In vivo, 11.7 µg Au in the tumor tissue was found to catalyze S-nitrosoglutathione continuously, and 54 µM NO was checked out in the urine. Results and Discussion: The high concentration of NO was found to increase the apoptotic rate and to reduce tumor proliferation. In the chemo-photothermal combination therapy, the tumor inhibition rate was increased up to 94.3%, and Au's contribution from catalyzing NO release NO was 8.17%.


Assuntos
Ouro/química , Neoplasias/patologia , Neoplasias/terapia , Óxido Nítrico/metabolismo , Catálise , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Ácido Fólico/química , Humanos , Células MCF-7 , Fenômenos Magnéticos , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Porosidade , Silício/química , Difração de Raios X
4.
Sensors (Basel) ; 21(8)2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33917654

RESUMO

Multisite neural probes are a fundamental tool to study brain function. Hybrid silicon/polymer neural probes combine rigid silicon and flexible polymer parts into one single device and allow, for example, the precise integration of complex probe geometries, such as multishank designs, with flexible biocompatible cabling. Despite these advantages and benefiting from highly reproducible fabrication methods on both silicon and polymer substrates, they have not been widely available. This paper presents the development, fabrication, characterization, and in vivo electrophysiological assessment of a hybrid multisite multishank silicon probe with a monolithically integrated polyimide flexible interconnect cable. The fabrication process was optimized at wafer level, and several neural probes with 64 gold electrode sites equally distributed along 8 shanks with an integrated 8 µm thick highly flexible polyimide interconnect cable were produced. The monolithic integration of the polyimide cable in the same fabrication process removed the necessity of the postfabrication bonding of the cable to the probe. This is the highest electrode site density and thinnest flexible cable ever reported for a hybrid silicon/polymer probe. Additionally, to avoid the time-consuming bonding of the probe to definitive packaging, the flexible cable was designed to terminate in a connector pad that can mate with commercial zero-insertion force (ZIF) connectors for electronics interfacing. This allows great experimental flexibility because interchangeable packaging can be used according to experimental demands. High-density distributed in vivo electrophysiological recordings were obtained from the hybrid neural probes with low intrinsic noise and high signal-to-noise ratio (SNR).


Assuntos
Polímeros , Silício , Eletrodos , Fenômenos Eletrofisiológicos
5.
Plant Physiol Biochem ; 162: 677-689, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33780741

RESUMO

Over the last decade, silicon (Si) has been widely accepted as a beneficial element for plant growth. The advantages plant derives from the Si are primarily based on the uptake and transport mechanisms. In the present study, the Si uptake regime was studied in finger millet (Eleusine coracana (L). Gaertn.) under controlled and stress conditions. The finger millet can efficiently uptake Si and accumulate it by more than 1% of dry weight in the leaf tissues, thus categorized as a Si accumulator. Subsequent evaluation with the single root assay revealed a three-fold higher Si uptake under osmatic stress than control. These results suggest that Si alleviated the PEG-induced stress by regulating the levels of osmolytes and antioxidant enzymes. Further, to understand the molecular mechanism involved in Si uptake, the Si influx (EcoLsi1 and EcoLsi6) and efflux transporters (EcoLsi2 and EcoLsi3) were identified and characterized. The comparative phylogenomic analysis of the influx transporter EcoLsi1 with other monocots revealed conserved features like aromatic/arginine (Ar/R) selectivity filters and pore morphology. Similarly, Si efflux transporter EcoLsi3 is highly homologous to other annotated efflux transporters. The transcriptome data revealed that the expression of both influx and efflux Si transporters was elevated due to Si supplementation under stress conditions. These findings suggest that stress elevates Si uptake in finger millet, and its transport is also regulated by the Si transporters. The present study will be helpful to better explore Si derived benefits in finger millet.


Assuntos
Eleusine , Pressão Osmótica , Filogenia , Silício , Transcriptoma
6.
J Vis Exp ; (168)2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33645554

RESUMO

Scanning electrochemical microscopy (SECM) is used to measure the local electrochemical behavior of liquid/solid, liquid/gas and liquid/liquid interfaces. Atomic force microscopy (AFM) is a versatile tool to characterize micro- and nanostructure in terms of topography and mechanical properties. However, conventional SECM or AFM provides limited laterally resolved information on electrical or electrochemical properties at nanoscale. For instance, the activity of a nanomaterial surface at crystal facet levels is difficult to resolve by conventional electrochemistry methods. This paper reports the application of a combination of AFM and SECM, namely, AFM-SECM, to probe nanoscale surface electrochemical activity while acquiring high-resolution topographical data. Such measurements are critical to understanding the relationship between nanostructure and reaction activity, which is relevant to a wide range of applications in material science, life science and chemical processes. The versatility of the combined AFM-SECM is demonstrated by mapping topographical and electrochemical properties of faceted nanoparticles (NPs) and nanobubbles (NBs), respectively. Compared to previously reported SECM imaging of nanostructures, this AFM-SECM enables quantitative assessment of local surface activity or reactivity with higher resolution of surface mapping.


Assuntos
Eletroquímica/métodos , Microscopia de Força Atômica , Microscopia Eletroquímica de Varredura , Nanoestruturas/ultraestrutura , Cobre/química , Eletrólitos/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Nanoestruturas/química , Oxirredução , Silício/química , Software
7.
J Vis Exp ; (168)2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33645586

RESUMO

Current automated radiosynthesizers are designed to produce large clinical batches of radiopharmaceuticals. They are not well suited for reaction optimization or novel radiopharmaceutical development since each data point involves significant reagent consumption, and contamination of the apparatus requires time for radioactive decay before the next use. To address these limitations, a platform for performing arrays of miniature droplet-based reactions in parallel, each confined within a surface-tension trap on a patterned polytetrafluoroethylene-coated silicon "chip", was developed. These chips enable rapid and convenient studies of reaction parameters including reagent concentrations, reaction solvent, reaction temperature and time. This platform permits the completion of hundreds of reactions in a few days with minimal reagent consumption, instead of taking months using a conventional radiosynthesizer.


Assuntos
Radioquímica/métodos , Indicadores e Reagentes , Compostos Radiofarmacêuticos/química , Silício/química , Solventes , Temperatura
8.
J Environ Manage ; 287: 112343, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33744819

RESUMO

Potentially toxic elements (PTE) toxicity has serious effects for human health. Si has been tested to investigate their ability to mitigate Cd and As contamination of rice. In this study, the combined effect of Si and melatonin (MT) on Cd and As uptake and transport in rice plants is tested in two contaminated soils via controlled pot experiments. Results showed that a combined Si and MT treatment (Si + MT) was more effective at reducing Cd and As uptake and transport than Si alone. The treatment had the strongest effect on Cd concentrations in rice grains from high-polluted soil (HP) when treated at the flowering stage (81.8% reduction) and from low-polluted soil (LP) at the tillering stage (TS, 64.9%). The greatest reduction of grain As was found when treated at TS in both soils, by 58.2% and 39.2% in HP and LP soil, respectively. The significant upregulation of CAT, SOD, and POD activities, and downregulation of MDA by Si + MT was more effective than that of Si alone; Si + MT significantly decreased expressions of Nramp1, HMA2, and IRT2 in roots in both soils, and also Nramp5, HMA3, and IRT1 in LP soil, which might result in Si+MT effect on Cd and As accumulation. However, Si + MT had little effect on the amino acid content of grains compared to Si alone. Overall, the combination of Si and MT was substantially more effective at reducing Cd and As uptake and transport than Si alone, especially in HP soil. This effect might result from the regulation of antioxidant potential and gene expression relating Cd uptake and transport.


Assuntos
Melatonina , Oryza , Poluentes do Solo , Cádmio/análise , Cádmio/toxicidade , Oryza/genética , Silício , Solo , Poluentes do Solo/análise
9.
Sensors (Basel) ; 21(4)2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33668578

RESUMO

Application of micro-Raman spectroscopy for the monitoring of quality of nanowire sensor chips fabrication has been demonstrated. Nanowire chips have been fabricated on the basis of «silicon-on-insulator¼ (SOI) structures (SOI-NW chips). The fabrication of SOI-NW chips was performed by optical litography with gas-phase etching. The so-fabricated SOI-NW chips are intended for highly sensitive detection of brain cancer biomarkers in humans. In our present study, two series of experiments have been conducted. In the first experimental series, detection of a synthetic DNA oligonucleotide (oDNA) analogue of brain cancer-associated microRNA miRNA-363 in purified buffer solution has been performed in order to demonstrate the high detection sensitivity. The second experimental series has been performed in order to reveal miRNA-363 itself in real human plasma samples. To provide detection biospecificity, the SOI-NW chip surface was modified by covalent immobilization of probe oligonucleotides (oDNA probes) complementary to the target biomolecules. Using the SOI-NW sensor chips proposed herein, the concentration detection limit of the target biomolecules at the level of 3.3 × 10-17 M has been demonstrated. Thus, the approach employing the SOI-NW chips proposed herein represents an attractive tool in biomedical practice, aimed at the early revelation of oncological diseases in humans.


Assuntos
Técnicas Biossensoriais , Neoplasias Encefálicas , MicroRNAs , Nanofios , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Humanos , MicroRNAs/genética , Plasma , Controle de Qualidade , Silício , Análise Espectral Raman
10.
Sensors (Basel) ; 21(4)2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33668616

RESUMO

This review summarizes the leading advancements in porous silicon (PSi) optical-biosensors, achieved over the past five years. The cost-effective fabrication process, the high internal surface area, the tunable pore size, and the photonic properties made the PSi an appealing transducing substrate for biosensing purposes, with applications in different research fields. Different optical PSi biosensors are reviewed and classified into four classes, based on the different biorecognition elements immobilized on the surface of the transducing material. The PL signal modulation and the effective refractive index changes of the porous matrix are the main optical transduction mechanisms discussed herein. The approaches that are commonly employed to chemically stabilize and functionalize the PSi surface are described.


Assuntos
Técnicas Biossensoriais , Silício , Fótons , Porosidade
11.
Plant Physiol Biochem ; 162: 110-123, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33667964

RESUMO

Salt stress limits plant growth and productivity by severely impacting the fundamental physiological processes. Silicon (Si) supplementation is considered one of the promising methods to improve plant resilience under salt stress. Here, the role of Si in modulating physiological and biochemical processes that get adversely affected by high salinity, is discussed. Although numerous reports show the beneficial effects of Si under stress, the precise molecular mechanism underlying this is not well understood. Questions like whether all plants are equally benefitted with Si supplementation despite having varying Si uptake capability and salinity tolerance are still elusive. This review illustrates the Si uptake and accumulation mechanism to understand the direct or indirect participation of Si in different physiological processes. Evaluation of plant responses at transcriptomics and proteomics levels are promising in understanding the role of Si. Integration of physiological understanding with omics scale information highlighted Si supplementation affecting the phytohormonal and antioxidant responses under salinity as a key factor defining improved resilience. Similarly, the crosstalk of Si with lignin and phenolic content under salt stress also seems to be an important phenomenon helping plants to reduce the stress. The present review also addressed various crucial mechanisms by which Si application alleviates salt stress, such as a decrease in oxidative damage, decreased lipid peroxidation, improved photosynthetic ability, and ion homeostasis. Besides, the application and challenges of using Si-nanoparticles have also been addressed. Comprehensive information and discussion provided here will be helpful to better understand the role of Si under salt stress.


Assuntos
Estresse Salino , Silício , Antioxidantes , Salinidade , Tolerância ao Sal , Silício/farmacologia
12.
Plant Physiol Biochem ; 162: 36-47, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33667965

RESUMO

Unfavorable environmental conditions are the critical inimical to the sustainable agriculture. Among various novel strategies designed to protect plants from abiotic stress threats, use of mineral elements as 'stress mitigators' has emerged as the most crucial and interesting aspect. Silicon (Si) is a quasi-essential nutrient that mediates plant growth and development and interacts with plant growth regulators (PGRs) and signaling molecules to combat abiotic stress induced adversities in plants and increase stress tolerance. PGRs are one of the most important chemical messengers that mediate plant growth and development during stressful conditions. However, the individual roles of Si and PGRs have extensively defined but their exquisite crosstalk with each other to mediate plant stress responses is still indiscernible. The present review is an upfront effort to delineate an intricate crosstalk/interaction between Si and PGRs to reduce abiotic stress adversities. The combined effects of interaction of Si with other signaling molecules such as reactive oxygen species (ROS), nitric oxide (NO) and calcium (Ca2+) for the survival of plants under stress and optimal conditions are also discussed.


Assuntos
Reguladores de Crescimento de Planta , Silício , Desenvolvimento Vegetal , Plantas , Silício/farmacologia , Estresse Fisiológico
13.
Ying Yong Sheng Tai Xue Bao ; 32(3): 1096-1104, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33754577

RESUMO

Silicon (Si) application could significantly alleviate the toxic effects of cadmium (Cd) on the growth and development of rice. Here, we examined the regulatory effects of Si on Cd accumulation and stress response in rice seedlings through a hydroponic root separation test. The results showed that the biomass of rice seedlings decreased significantly under Cd stress, while the addition of Si could alleviate such negative effect. The uptake, transfer, and accumulation of Cd in rice seedling were significantly affected by Si addition under Cd stress. Si application under the unilateral Cd stress (Si-Cd+Si, Si-Cd) increased Cd-retention coefficient of root by 83.3%-83.6%, which restricted the transfer of Cd from root to aboveground. However, the treatment with Si added to the non-stressed side (Si-Cd) elevated the uptake and accumulation of Cd in rice seedling, with the accumulation in root being increased by 48.2% when compared to the treatment under the unilateral Cd stress without the addition of Si (CK-Cd). The treatment with Si added in two sides (Si-Cd+Si) decreased the uptake of Cd both in root and aboveground parts by 36.7% and 54.9%, respectively. The addition of Si under bilateral Cd stress (Cd-Cd+Si) significantly reduced the Cd uptake of both the root and aboveground parts by 57.8% and 46.5%, respectively, compared to the treatment of bilateral Cd stress (Cd-Cd). Higher Si concentration in rice seedling was found under the Cd stress. More Si was accumulated in rice seedling to resist the Cd stress when Si was added. The addition of Si affected the absorption of other metal elements in rice seedlings, including calcium (Ca), magnesium (Mg) and manganese (Mn). The concentrations of Ca and Mg in root and aboveground parts were significantly increased by Si addition under bilateral Cd-stress (Cd-Cd+Si), but Mn concentration was changed with the stress degree of Cd. The activities of superoxide dismutase (SOD) and peroxidase (POD) in root were affected by Si under Cd stress, especially for the Si-Cd treatment. The activity of POD in the root of the Cd-stress side and that of SOD in non-stress side were significantly increased, which benefit to scavenging the free radicals induced by Cd stress. In conclusion, Si could regulate the growth of rice seedlings, the uptake of elements such as Cd and Si, and the antioxidant reaction of the root system under the Cd stress. High Si concentration in plant is conducive to enhancing Cd tolerance.


Assuntos
Oryza , Poluentes do Solo , Cádmio/toxicidade , Estresse Oxidativo , Raízes de Plantas , Plântula , Silício/farmacologia , Poluentes do Solo/toxicidade
14.
ACS Appl Mater Interfaces ; 13(7): 8049-8059, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33570931

RESUMO

Label-free optical detection of biomolecules is currently limited by a lack of specificity rather than sensitivity. To exploit the much more characteristic refractive index dispersion in the mid-infrared (IR) regime, we have engineered three-dimensional IR-resonant silicon micropillar arrays (Si-MPAs) for protein sensing. By exploiting the unique hierarchical nano- and microstructured design of these Si-MPAs attained by CMOS-compatible silicon-based microfabrication processes, we achieved an optimized interrogation of surface protein binding. Based on spatially resolved surface functionalization, we demonstrate controlled three-dimensional interfacing of mammalian cells with Si-MPAs. Spatially controlled surface functionalization for site-specific protein immobilization enabled efficient targeting of soluble and membrane proteins into sensing hotspots directly from cells cultured on Si-MPAs. Protein binding to Si-MPA hotspots at submonolayer level was unambiguously detected by conventional Fourier transform IR spectroscopy. The compatibility with cost-effective CMOS-based microfabrication techniques readily allows integration of this novel IR transducer into fully fledged bioanalytical microdevices for selective and sensitive protein sensing.


Assuntos
Técnicas Biossensoriais , Proteínas de Fluorescência Verde/isolamento & purificação , Análise Serial de Proteínas , Silício/química , Campos Eletromagnéticos , Proteínas de Fluorescência Verde/química , Células HeLa , Humanos , Imagem Óptica , Tamanho da Partícula , Propriedades de Superfície , Células Tumorais Cultivadas
15.
Int J Nanomedicine ; 16: 763-773, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33574664

RESUMO

Introduction: The sensitive interfacial interaction of liquid crystals (LC) holds potential for precision biosensors. In the past, the developments of LC biosensors were limited by the complicated manufacturing process, which hinders commercialization and wider applications of such devices. In this report, we demonstrate the first nano-structural polymeric stabilized-cholesteric LC (PSCLC) thin films to be a new label-free biosensing technology. Methods: The transmission spectra of PSCLC devices were measured by the fiber-optic spectrometer with high-resolution. In addition, a smartphone was set on the stage, and the camera of smartphone was placed and aligned with a set of lenses embedded in the designed stage. To decrease the chromatic and spherical aberrations, an achromatic lens set composition, consisting of both dual-convex lens and concave-plane lens, was applied for measuring and imaging the PSCLC texture. The average and the estimated standard deviation (SD) were used to present quantitative experimental results. The test BSA was immobilized and fulfilled by the ceramic silicon-constructed DMOAP-coated glass in aqueous BSA solutions at 1 mg/mL, 1 µg/mL, and 1 ng/mL. Results: The fabrication process of PSCLC is much simplified compared to previous LC biosensors. The color of PSCLC biosensor altered with the BSA concentration, making detection result easy to read. The detection limit of 1 ng/mL is achieved for label-free PSCLC biosensor. The PSCLC biosensor was able to successfully detect due to the albumin concentration's alteration, with a linear range of 1 ng/mL-2 mg/mL. Thus, the label-free-proposed design-integrated nanoscale PSCLCs smartphone-based biosensor could successfully detect BSA in a preclinical urine sample. Conclusion: Finally, we propose a design to integrate the PSCLC biosensor with a smartphone. The PSCLC owns potential for high performance, low cost for detecting various disease biomarkers in home use. Owing to its great potential for high performance and low cost, the PSCLC biosensors can be used as a label-free point-of-care for detecting various disease biomarkers for patients in care homes.


Assuntos
Albuminas/análise , Técnicas Biossensoriais , Cerâmica/química , Cristais Líquidos/química , Nanoestruturas/química , Silício/química , Smartphone , Compostos de Trimetilsilil/química , Animais , Técnicas Biossensoriais/métodos , Humanos , Imunoensaio , Masculino , Polímeros/química , Ratos Wistar , Soroalbumina Bovina/urina , Silanos/química
16.
Ecotoxicol Environ Saf ; 212: 111962, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33550082

RESUMO

The production of cucumber under combined salinity and heat stress is a crucial challenge facing many countries particularly in arid environments. This challenge could be controlled through exogenous foliar application of some bio-stimulants or anti-stressors. This study was carried out to investigate the management and improving cucumber production under combined salinity and heat stress. Nano-selenium (nano-Se, 25 mg L-1), silicon (Si, 200 mg L-1) and hydrogen peroxide (H2O2, 20 mmol L-1) were foliar applied on cucumber plants as anti-stress compounds. The results revealed that studied anti-stressors improved growth and productivity of cucumber grown in saline soil regardless the kind of anti-stressor under heat stress. The foliar application of nano-Se (25 mg L-1) clearly improved cucumber growth parameters (plant height and leaf area) compared to other anti-stressor and control. Foliar Si application showed the greatest impact on enzymatic antioxidant capacities among the other anti-stressor treatments. This applied rate of Si also showed the greatest increase in marketable fruit yield and yield quality (fruit firmness and total soluble solids) compared to untreated plants. These increases could be due to increasing nutrient uptake particularly N, P, K, and Mg, as well as Se (by 40.2% and 43%) in leaves and Si (by 11.2% and 22.1% in fruits) in both seasons, respectively. The potential role of Si in mitigating soil salinity under heat stress could be referred to high Si content found in leaf which regulates water losses via transpiration as well as high nutrient uptake of other nutrients (N, P, K, Mg and Se). The distinguished high K+ content found in cucumber leaves might help stressed plants to tolerate studied stresses by regulating the osmotic balance and controlling stomatal opening, which support cultivated plants to adapt to soil salinity under heat stress. Further studies are needed to be carried out concerning the different response of cultivated plants to combined stresses.


Assuntos
Selênio , Silício , Antioxidantes , Cucumis sativus/crescimento & desenvolvimento , Frutas , Resposta ao Choque Térmico/fisiologia , Peróxido de Hidrogênio , Folhas de Planta , Salinidade , Solo
17.
J Environ Manage ; 285: 112142, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33581457

RESUMO

Salinity is a major abiotic stress that adversely affects turfgrass growth. Clinoptilolite zeolite, a silicon (Si)-rich mineral, may allow these plants to cope with salinity. Therefore, in the present study, the effects of ordinary clinoptilolite zeolite (OZ) and potassium-enriched clinoptilolite zeolite (K-EZ) on the growth of perennial ryegrass (Lolium perenne L.) were assessed under salinity stress. Perennial ryegrass seeds were cultured in soil mixtures amended, or not, with OZ or K-EZ, then exposed to three salinity levels (0, 50 or 100 mM NaCl) for three months. Control plants were grown in the same soil mixture without zeolites, but not exposed to salinity. In salinity, the application of both types of zeolite significantly decreased Na content by 44.36% and 21.31%, but increased K content by 272.34% and 81.59%, as well as the K/Na ratio by 590.47% and 129.43%, in shoots and roots, respectively, compared to the no-zeolite treatment. Similarly, Si content in shoots increased by 28.33%. Amending the soil mixture with zeolite, especially K-EZ, enhanced relative water content, membrane stability index, total chlorophyll content, total soluble proteins, peroxidase and superoxide dismutase activities but reduced the contents of total soluble carbohydrates, hydrogen peroxide, and malondialdehyde in saline conditions. Shoot and root dry weight, root volume and root/shoot ratio also improved. Soil amendment with both forms of zeolite, as a Si-rich mineral, partially offset the negative impacts of salinity on perennial ryegrass, although K-EZ had more noticeable positive and beneficial effects. The amendment of growth media with zeolite may be an effective sustainable management practice for turfgrass used in landscaping and sports fields exposed to saline water.


Assuntos
Lolium , Zeolitas , Raízes de Plantas , Potássio , Salinidade , Estresse Salino , Silício
18.
Chemosphere ; 273: 129690, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33524757

RESUMO

Cadmium (Cd) is a primary contaminant in agricultural soils of the world. The ability of Cd uptake, transport, detoxification, and accumulation varies among different plant species and genotypes. Cd is translocated from soil to root by different transporters which are used for essential plant nutrient uptake. A number of strategies have been suggested for decreasing Cd toxicity in Cd contaminated soils. Recently, a lot of research have been carried out on minimizing Cd uptake through selenium (Se) and silicon (Si) applications. Both Se and Si have been reported to mitigate Cd toxicity in different crops. Vacuolar sequestration, formation of phytochelatins, and cell wall adsorption have been reported as effective mechanisms for Cd detoxification. The present review discussed past and current knowledge of literature to better understand Cd toxicity and its mitigation by adopting different feasible and practical approaches.


Assuntos
Oryza , Selênio , Poluentes do Solo , Cádmio/análise , Cádmio/toxicidade , Fitoquelatinas , Silício , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
19.
Environ Pollut ; 276: 116700, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33621736

RESUMO

Porous silicon-coated zero-valent iron (Fe0@p-SiO2) is a promising material for in-situ contaminated groundwater remediation. However, investigations of factors that affect the transport of Fe0@p-SiO2 remain incomplete. In the present study, Fe0@p-SiO2 composites were prepared by a SiO2-coated technology, and a series of column experiments were conducted to examine the effects of media size, ionic strength, and injection velocity and concentration on retention and transport in saturated porous media. Results showed that the obtained Fe0@p-SiO2 is a core-shell composite with zero-valent iron as the core and porous silicon as the shell. Media size, injection velocity, Fe0 concentration, and ionic strength had a significant impact on the transport of Fe0@p-SiO2. Fe0@p-SiO2 effluent concentrations decreased with a smaller media size. Increasing initial particle concentration and ionic strength led to a decrease in particle transport. High particle retention was observed near the middle of the column, especially with high injection concentration. That was also observable in the condition of lower injection velocity or finer media. The results indicated that two transport behaviors during particles transport, which were "agglomeration-straining" and "detachment-re-migration". Moreover, the dominated mechanisms for Fe0@p-SiO2 transport and retention in saturated porous media are hydrodynamic dispersion and interception. Given the results, in practical engineering applications, proper injection velocity and concentration should be selected depending on the pollution status of groundwater and the geochemical environment to ensure an effective in-situ reaction zone.


Assuntos
Água Subterrânea , Ferro , Tamanho da Partícula , Porosidade , Silício , Dióxido de Silício
20.
J Vis Exp ; (167)2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33586701

RESUMO

Myofibroblasts can spontaneously internalize silicon nanowires (SiNWs), making them an attractive target for bioelectronic applications. These cell-silicon hybrids offer leadless optical modulation capabilities with minimal perturbation to normal cell behavior. The optical capabilities are obtained by the photothermal and photoelectric properties of SiNWs. These hybrids can be harvested using standard tissue culture techniques and then applied to different biological scenarios. We demonstrate here how these hybrids can be used to study the electrical coupling of cardiac cells and compare how myofibroblasts couple to one another or to cardiomyocytes. This process can be accomplished without special equipment beyond a fluorescent microscope with coupled laser line. Also shown is the use of a custom-built MATLAB routine that allows the quantification of calcium propagation within and between the different cells in the culture. Myofibroblasts are shown to have a slower electrical response than that of cardiomyocytes. Moreover, the myofibroblast intercellular propagation shows slightly slower, though comparable velocities to their intracellular velocities, suggesting passive propagation through gap junctions or nanotubes. This technique is highly adaptable and can be easily applied to other cellular arenas, for in vitro as well as in vivo or ex vivo investigations.


Assuntos
Células/metabolismo , Fenômenos Eletrofisiológicos , Nanofios/química , Óptica e Fotônica , Silício/química , Animais , Cálcio/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Miofibroblastos/citologia , Miofibroblastos/metabolismo , Imagem Óptica , Gravação em Vídeo
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