Silicon Era of Carbon-Based Life: Application of Genomics and Bioinformatics in Crop Stress Research

Abiotic and biotic stresses lead to massive reprogramming of different life processes and are the major limiting factors hampering crop productivity. Omics-based research platforms allow for a holistic and comprehensive survey on crop stress responses and hence may bring forth better crop improvement strategies. Since high-throughput approaches generate considerable amounts of data, bioinformatics tools will play an essential role in storing, retrieving, sharing, processing, and analyzing them. Genomic and functional genomic studies in crops still lag far behind similar studies in humans and other animals. In this review, we summarize some useful genomics and bioinformatics resources available to crop scientists. In addition, we also discuss the major challenges and advancements in the “-omics” studies, with an emphasis on their possible impacts on crop stress research and crop improvement.     

Role of Silica Nanoparticles in Abiotic and Biotic Stress Tolerance in Plants: A Review

The demand for agricultural crops continues to escalate with the rapid growth of the population. However, extreme climates, pests and diseases, and environmental pollution pose a huge threat to agricultural food production. Silica nanoparticles (SNPs) are beneficial for plant growth and production and can be used as nanopesticides, nanoherbicides, and nanofertilizers in agriculture. This article provides a review of the absorption and transportation of SNPs in plants, as well as their role and mechanisms in promoting plant growth and enhancing plant resistance against biotic and abiotic stresses. In general, SNPs induce plant resistance against stress factors by strengthening the physical barrier, improving plant photosynthesis, activating defensive enzyme activity, increasing anti-stress compounds, and activating the expression of defense-related genes. The effect of SNPs on plants stress is related to the physical and chemical properties (e.g., particle size and surface charge) of SNPs, soil, and stress type. Future research needs to focus on the “SNPs–plant–soil–microorganism” system by using omics and the in-depth study of the molecular mechanisms of SNPs-mediated plant resistance.     

Photoinduced Processes in Silicon Nanoparticles

Silicon nanocrystals have been prepared from gas-phase pyrolysis and electrochemical etching of silicon. Confocal and wide-field optical microscopy have been performed on size-selected ensembles and single silicon nanocrystals. Single particles exhibit photoluminescence blinking effects that are interrelated with photo-induced (reversible) bleaching effects of the ensemble. The blinking dynamics follow a power law statistic of on- and off-times, revealing that even single nanoparticles are subject to strong disorder effects. This is supported by optically detected magnetic resonance (ODMR) experiments on silicon nanoparticles achieved for the first time via microscopic techniques.     

Predicting Failure Stress of Silicon Nitride Ceramics Using Microfocus Radiography

Microfocus projection radiography was used to evaluate nondestructively a large quantity of silicon nitride modulus-of-rupture test bars. Quantitative data (size, shape, and location) on major naturally occurring voids in rejected bars were determined from radiographs. Failure stress prediction was attempted using a fracture mechanics model and nondestructive evaluation data and compared to actual failure stress.     

Processing Methods of Silicon to its Ingot: a Review

Silicon - Any metal must be processed from its ore before employing it in various industrial applications; this is the similar case with Silicon (Si) as well. Occurring in the form of silicates in...     

Size-Scaling of Tensile Failure Stress in a Hot-Pressed Silicon Carbide

Quasi-static Weibull strength-size scaling of hot-pressed silicon carbide is described. Two surface conditions (uniaxial ground and uniaxial ground followed by grit blasting) were explored. Strength test coupons sampled effective areas from the very small (4 × 10⁻³ mm²) to the very large (4 × 10⁴ mm²). Equibiaxial flexure and Hertzian ring crack initiation were used for the strength tests, and characteristic strengths for several different specimen geometries were analyzed as a function of effective area. Characteristic strength was found to substantially increase with decreased effective area for both surface conditions. Weibull moduli of 9.4- and 11.7 well-represented strength-size scaling for the two ground conditions between an effective area range of 10⁻¹ and 4 × 10⁴ mm². Machining damage was observed to be the dominant flaw type over this range. However, for effective areas <10⁻¹ mm², the characteristic strength increased rapidly for both ground surface conditions as the effective area decreased, and one or more of the inherent assumptions behind the classical Weibull strength-size scaling were in violation in this range. The selections of a ceramic strength to account for ballistically induced tile deflection and expanding cavity modeling are considered in context with the measured strength-size scaling. The observed size-scaling is briefly discussed with reference to dynamic strength.     

Residual Stress Measurements in Alumina and Silicon Carbide

Residual stresses were measured in three types of ceramic components. Stresses were measured using X-ray diffraction and an advanced X-ray instrument. Measured stresses in alumina rods were shown to correlate well with breaking strength, and stress variations in an alumina tile were hypothesized to result from inhomogeneous cooling. The compressive stresses induced in a silicon carbide tube, by an outer steel sleeve, were seen to be balanced by tensile stresses in the sleeve.     

Immunomodulation of Melanoma by Chemo-Thermo-Immunotherapy Using Conjugates of Melanogenesis Substrate NPrCAP and Magnetite Nanoparticles: A Review

A major advance in drug discovery and targeted therapy directed at cancer cells may be achieved by the exploitation and immunomodulation of their unique biological properties. This review summarizes our efforts to develop novel chemo-thermo-immunotherapy (CTI therapy) by conjugating a melanogenesis substrate, N-propionyl cysteaminylphenol (NPrCAP: amine analog of tyrosine), with magnetite nanoparticles (MNP). In our approach, NPrCAP provides a unique drug delivery system (DDS) because of its selective incorporation into melanoma cells. It also functions as a melanoma-targeted therapeutic drug because of its production of highly reactive free radicals (melanoma-targeted chemotherapy). Moreover, the utilization of MNP is a platform to develop thermo-immunotherapy because of heat shock protein (HSP) expression upon heat generation in MNP by exposure to an alternating magnetic field (AMF). This comprehensive review covers experimental in vivo and in vitro mouse melanoma models and preliminary clinical trials with a limited number of advanced melanoma patients. We also discuss the future directions of CTI therapy.     

High-efficiency Silicon Solar Cells: A Review

Over the past few decades, crystalline silicon solar cells have been extensively studied due to their high efficiency, high reliability, and low cost. In addition, these types of cells lead the industry and account for more than half of the market. For the foreseeable future, Si will still be a critical material for photovoltaic devices in the solar cell industry. In this paper, we discuss key issues, cell concepts, and the status of recent high-efficiency crystalline silicon solar cells.     

利用粉煤灰和作物秸秆研制含硅有机复合肥

简要介绍了粉煤灰和秸秆的利用现状,着重介绍用其制备含硅有机复合肥的多种生产方法以及肥料本身的特性,指出目前其存在的问题,以及未来发展前景.     

Binding Graphene Sheets Together Using Silicon: Graphene/Silicon Superlattice

We propose a superlattice consisting of graphene and monolayer thick Si sheets and investigate it using a first-principles density functional theory. The Si layer is found to not only strengthen the interlayer binding between the graphene sheets compared to that in graphite, but also inject electrons into graphene, yet without altering the most unique property of graphene: the Dirac fermion-like electronic structure. The superlattice approach represents a new direction for exploring basic science and applications of graphene-based materials.     

Synthesis and Characterisation of In Situ Doped Silicon Nanoparticles

In situ boron, or phosphorous doped silicon nanoparticles were synthesised by pyrolysis of monosilane-diborane and monosilane-phosphane mixtures in free-space reactors. The studies were performed under atmospheric pressure in a laboratory reactor and a pilot plant for examination of scale-up effects. In the laboratory scale experiments, 1 vol % monosilane diluted in helium was used. The synthesis temperature varied between 600 and 800 ^°C. Pilot plant tests were run at 600 ^°C with 13.3 vol % silane diluted in hydrogen. The dopant content of the synthesised silicon powders was characterised by ETV-ICP-OES. Further investigations were carried out by using SEM, XRD, particle size analysis and FT-IR. An inhibition of the boron incorporation into the growing silicon lattice was found during the decomposition of the silane-diborane mixtures. This effect is a result of the low thermal stability of diborane. Silicon powders with higher boron contents and a wider particle size distribution leading to bigger particles, which showed no affinity to electrostatic charging, were obtained on the pilot plant scale. In phosphorus doping, reactor temperature was found crucial for the doping process.     

Silicon Nanoparticles and Methyl Jasmonate Improve Physiological Response and Increase Expression of Stress-related Genes in Strawberry cv. Paros Under Salinity Stress

Silicon - Salinity is one of the most crucial abiotic stresses, which is the consequence of an increase in the concentration of NaCl ions, influencing the plant’s growth, development, and...     

Expanding Gene-Editing Potential in Crop Improvement with Pangenomes

Pangenomes aim to represent the complete repertoire of the genome diversity present within a species or cohort of species, capturing the genomic structural variance between individuals. This genomic information coupled with phenotypic data can be applied to identify genes and alleles involved with abiotic stress tolerance, disease resistance, and other desirable traits. The characterisation of novel structural variants from pangenomes can support genome editing approaches such as Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR associated protein Cas (CRISPR-Cas), providing functional information on gene sequences and new target sites in variant-specific genes with increased efficiency. This review discusses the application of pangenomes in genome editing and crop improvement, focusing on the potential of pangenomes to accurately identify target genes for CRISPR-Cas editing of plant genomes while avoiding adverse off-target effects. We consider the limitations of applying CRISPR-Cas editing with pangenome references and potential solutions to overcome these limitations.     

Stress Rate and Proof-Testing of Silicon Wafers

Fracture mechanics test methods were applied to evaluate the proof-test characteristics of single-crystal silicon wafers. The results indicate that the strength distribution of silicon wafers is truncated by proof-testing. No subcritical crack growth occurred during proof-loading, as inferred from the lack of a stress-rate effect on strength. Mechanical proof-testing appears to be an effective method for eliminating weak samples before cell processing.