Incapacitating Agents and Technologies: A Review *
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
PCSI materials can be blown into the atmosphere as fine particulates using fogging machines. This means of dissemination of PCSI materials avoids toxic effects from inhaled combustion products, which are a feature of grenade-generated smokes. For large-scale applications, the PCSI material can be mixed with a hydrophobic anti-agglomerative material such as Neocil (fumed silica) to improve flow properties. For example, Agent CS formulations (CS1 and CS2) have been produced for use in fogging machines. Agent CS1 is a micronized powder containing 5% hydrophobic silica aerogel, which persists for about 2 weeks; Agent CS2 is a siliconized microencapsulated form of Agent CS1 with improved flow properties and greater weather resistance, composed of 95% micropulverized Agent CS with silica-treated hexamethyldisilazane. Because they persist in the environment, these formulations are not suitable for civilian peacekeeping operations but are used to create a persistent impediment in military operations (Blumenfeld and Meselson, 1971; Ministry of Defence, 1972). On a smaller scale, and mainly for self-defense purposes, “tear gas pen guns” or “tear gas pistols” are available in some countries. These devices have an explosive charge that propels a cloud of irritant material toward the assailant. They have high physical injury potential and have caused severe local skin and eye injuries (Rengstorff, 1969).
Biotechnology
Massimo Maffei in Vetiveria, 2002
Callus suspension cultures were established by transferring 6 g (fresh weight) callus in 80 ml of MS medium containing 2% sucrose (w/v) and modified according to Mucciarelli et al. (1993). Suspension cultures were maintained on a gyratory shaker at 25 rpm for 30 days. Amberlite XAD-4, tried as a growth elicitor, has been tested in activated and non-activated form and added sterile at 2% (w/v) in liquid cultures (Camusso et al., 1999; Camusso et al., in preparation). Glucidic compositions of cell culture and suspension media were determined by fractionating extraction and enzymatic hydrolysis and analysis by GC-MS, after resuspension in pyridine and derivatization by 1,1,1,3,3,3-hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS).
Gas Chromatography
Joseph Chamberlain in The Analysis of Drugs in Biological Fluids, 2018
Obviously, high loadings of stationary phase will help solve the problem of absorption on the support, but such high loadings may not be desirable for the required chromatography. It is therefore more usual to inactivate the support itself, prior to coating with stationary phase, by silylating with hexamethyldisilazane or similar reagent. The glass column itself should be similarly treated.
Inhibitory effects of vorinostat (SAHA) against food-borne pathogen Salmonella enterica serotype Kentucky mixed culture biofilm with virulence and quorum-sensing relative expression
Published in Biofouling, 2023
Pantu Kumar Roy, Angela Ji-Won Ha, Shamsun Nahar, Md. Iqbal Hossain, Md. Ashrafudoulla, Sazzad Hossen Toushik, Md. Furkanur Rahaman Mizan, Iksoon Kang, Sang-Do Ha
This experiment was performed using an FE-SEM (Carl Zeiss, Oberkochen, Germany) method following previous studied (Byun et al. 2021) to confirm the effects of SAHA on the food-contact (abiotic) and food surfaces (biotic). Samples were prepared by a series of fixing and dehydrating steps. For prefixation, samples were kept for 4 h in a 2% glutaraldehyde solution (Sigma, St. Louis, MO, USA) at room temperature. Prefixation was achieved by washing the samples in PBS for 10 min each time. After that, post-fixation was done for 2 h with a 2% osmium tetroxide solution (Sigma) at room temperature and washed with PBS for 10 min. Then the samples were successively dehydrated with ethanol solutions (50, 60, 70, 80 and 90% ethanol, respectively). Following that, samples were treated three times with 100% ethanol. For 15 min, the samples were submerged in ethanol and hexamethyldisilazane (Sigma) in 3:1, 1:1 and 1:3 ratios. Three final treatments with 100% hexamethyldisilazane were carried out. Carbon tape was used to secure samples to an aluminum stub, and the samples were then coated with palladium gold. The FE-SEM equipment was operated at a 5 kV acceleration voltage at a 5-mm working distance (Ashrafudoulla et al. 2021).
Pathogenic Effects and Pathogenesis Processes in Vitro & in Vivo in Murine Cytomegalovirus Infected Rat Corneal Endothelial Cells
Published in Ocular Immunology and Inflammation, 2022
Qing Lu, Bin-Jia Sun, Yue-Peng Zhou, Xuan Jiang, Rong-Mei Peng, Shuang Zhang, Min-Hua Luo, Jing Hong
Samples were processed for SEM analysis by exposure twice to hexamethyldisilazane followed by air drying, mounting on aluminum stubs, and sputter coating with gold. For TEM analysis, samples were embedded in epoxy resin, and ultrathin sections (50–70 nm) were collected on copper grids. Counterstaining was carried out with aqueous uranyl acetate and phosphotungstic acid for 1 hour each followed by Reynolds’ lead citrate for 20 minutes. The samples from the control group were processed in the same manner as the experimental samples. The areas of corneal endothelial cells (four files, five cells each filed) were measured by Image J 1.52 t (National Institutes of Health, Rockville, Maryland, USA). Twenty cells were measured randomly each group then analyzed by SPSS 16.0 and GraphPad Prism 8.0.
Anti-biofilm activity of a novel pit and fissure self-adhesive sealant modified with metallic monomers
Published in Biofouling, 2020
Alexandra Rubin Cocco, Carlos Enrique Cuevas-Suárez, Yuan Liu, Rafael Guerra Lund, Evandro Piva, Geelsu Hwang
To check the effect of the SnM 5% on biofilm morphology, S. mutans single-species biofilms were formed on HA discs with or without SnM 5% coating as described above and performed SEM analysis (Liu et al. 2016). Briefly, after harvesting biofilms at 42 h, the biofilms were fixed using 2.5% glutaraldehyde and 2.0% paraformaldehyde for 4 h. Then, the biofilms were washed three times in ultrapure water, from a Milli-Q system (18.2 MΩ cm, Millipore, USA), and serially dehydrated with 50%, 70%, 80%, 90% and 100% ethanol for 10 min each. The discs were then dried with mixtures of ethanol:hexamethyldisilazane (1:1 and 1:4) (Polysciences, Inc., Warrington, PA, USA), and 100% of hexamethyldisilazane for 10 min each. The discs were dried for 1 h at room temperature, and then they were mounted on a microscope holder. Finally, the interface between discs and holder was coated with Colloidal Silver-liquid (Industry Road, Hatfield, PA, USA). Biofilms on each disc were observed by scanning electron microscopy (SEMTM) (Quanta FEG 250, FEI, Hillsboro, OR).
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