silicon and Poisoning

Abiotic stresses, such as salinity, heavy metals and drought, are some of the most devastating factors hindering sustainable crop production today. Plants use their own defensive strategies to cope with the adverse effects of these stresses, via the regulation of the expression of essential phytohormones, such as gibberellins (GA), salicylic acid (SA), jasmonates (JA), abscisic acid (ABA) and ethylene (ET). However, the efficacy of the endogenous defensive arsenals of plants often falls short if the stress persists over an extended period. Various strategies are developed to improve stress tolerance in plants. For example, silicon (Si) is widely considered to possess significant potential as a substance which ameliorate the negative effects of abiotic stresses, and improves plant growth and biomass accumulation. This review aims to explain how Si application influences the signaling of the endogenous hormones GA, SA, ABA, JA and ET during salinity, wounding, drought and metal stresses in crop plants. Phytohormonal cross talk plays an important role in the regulation of induced defences against stress. However, detailed molecular and proteomic research into these interactions is needed in order to identify the underlying mechanisms of stress tolerance that is imparted by Si application and uptake.

Topics: Crops, Agricultural; Heavy Metal Poisoning; Plant Growth Regulators; Poisoning; Salinity; Silicon; Stress, Physiological

Because toxic heavy metals tend to bioaccumulate, they represent a substantial human health hazard. Various methods are used to identify and quantify toxic metals in biological tissues and environment fluids, but a simple, rapid, and inexpensive system has yet to be developed. To reduce the necessity for instrument-dependent analysis, we developed a single, pH-dependent, nanosphere (NS) sensor for naked-eye detection and removal of toxic metal ions from drinking water and physiological systems (i.e., blood). The design platform for the optical NS sensor is composed of double mesoporous core-shell silica NSs fabricated by one-pot, template-guided synthesis with anionic surfactant. The dense shell-by-shell NS construction generated a unique hierarchical NS sensor with a hollow cage interior to enable accessibility for continuous monitoring of several different toxic metal ions and efficient multi-ion sensing and removal capabilities with respect to reversibility, longevity, selectivity, and signal stability. Here, we examined the application of the NS sensor for the removal of toxic metals (e.g., lead ions from a physiological system, such as human blood). The findings show that this sensor design has potential for the rapid screening of blood lead levels so that the effects of lead toxicity can be avoided.

Topics: Blood Component Removal; Heavy Metal Poisoning; Humans; Metals, Heavy; Nanospheres; Optical Devices; Poisoning; Refractometry; Silicon; Transducers; Ultrafiltration

Experiments were conducted to determine whether dietary silicon will reduce the toxic effects of dietary aluminum on broiler chickens. The parameters measured were weight gain, feed efficiency, percentage bone ash, tibial dyschondroplasia, and the retention of calcium, phosphorus, and phytin phosphorus. Experiments 1 and 2 were conducted with casein and gelatin-based purified diets and Experiments 3 and 4 with corn and soybean meal-based practical diets. All experiments used day-old broiler cockerels and lasted 16 days. Aluminum significantly reduced weight gain, feed efficiency, and percentage bone ash in all four experiments. Aluminum supplementation reduced the incidence and severity of tibial dyschondroplasia, but this effect was associated with a reduction in weight gain. Increasing dietary aluminum reduced the retention of phosphorus and phytin phosphorus. Silicon did not alleviate the effects of aluminum toxicity on any of the parameters measured but did independently increase growth rate in Experiments 1 and 2, Supplementary dietary silicon does not appear to reduce aluminum toxicity in broiler chickens. Aluminum appears to exert its toxic effect on chickens by reducing the retention of phosphorus and phytin phosphorus.

Topics: Aluminum; Analysis of Variance; Animals; Chickens; Diet; Male; Osteochondrodysplasias; Poisoning; Poultry Diseases; Regression Analysis; Silicon; Tibia; Weight Gain

An 18-month-old infant required six hospital admissions in a period of six months for episodes consisting of coughing, respiratory depression, hematemesis, coma, dehydration, and lesions about the mouth. A negative history of ingestion of toxins was repeatedly obtained from the family and two home inspection by the local Health Department failed to identify potential toxins. Metabolic work-up was entirely negative. Utilizing methods of GC-MS, metabolites of a-terpineol were isolated from infant urine on two admissions to the hospital. These metabolites were confirmed by mass spectrometry to be the same metabolites excreted by Sprague-Dawley rats injected with a-terpineol or pine oil. The child had no additional episodes after physical separation from the home environment.

Topics: Animals; Brain; Brain Diseases; Chromatography, Gas; Humans; Infant; Male; Mass Spectrometry; Oils; Poisoning; Rats; Silicon; Terpenes; Trimethylsilyl Compounds

Topics: Heavy Metal Poisoning; Humans; Iron; Metals, Heavy; Poisoning; Silicon

Topics: Humans; Malpractice; Poisoning; Silicon