ABSTRACT
Materials that both sequester chemical warfare agents (CWAs) and then catalytically decontaminate the entrapped CWAs are highly sought. This article reports such a system for air-based catalytic removal of the sulfur mustard (HD) simulant, 2-chloroethyl ethyl sulfide (CEES). Hypercrosslinked polymers (HCPs) sequester CEES, and an HCP-embedded oxidation system comprising tribromide, nitrate, and acid (NOxBrxH+) simultaneously catalyzes the aerobic and selective, oxidative conversion of the entrapped CEES to the desired far less-toxic sulfoxide under ambient conditions (air and temperature). (NOxBrxH+) has been incorporated into three HCPs, a fluorobenzene HCP (HCP-F), a methylated HCP (HCP-M), and an HCP with acidic moieties (HCP-A). HCP-A acts as both an absorbing material and a catalytic component due to its acidic side chains. All three HCP/NOxBrxH+ systems work rapidly under these optimally mild conditions. No light or added oxidants are required. The HCP/NOxBrxH+ systems are recyclable.
ABSTRACT
Bis(2-chloroethyl) sulfide or sulfur mustard (HD) is one of the highest-tonnage chemical warfare agents and one that is highly persistent in the environment. For decontamination, selective oxidation of HD to the substantially less toxic sulfoxide is crucial. We report here a solvent-free, solid, robust catalyst comprising hydrophobic salts of tribromide and nitrate, copper(II) nitrate hydrate, and a solid acid (NafionTM) for selective sulfoxidation using only ambient air at room temperature. This system rapidly removes HD as a neat liquid or a vapor. The mechanisms of these aerobic decontamination reactions are complex, and studies confirm reversible formation of a key intermediate, the bromosulfonium ion, and the role of Cu(II). The latter increases the rate four-fold by increasing the equilibrium concentration of bromosulfonium during turnover. Cu(II) also provides a colorimetric detection capability. Without HD, the solid is green, and with HD, it is brown. Bromine K-edge XANES and EXAFS studies confirm regeneration of tribromide under catalytic conditions. Diffuse reflectance infrared Fourier transform spectroscopy shows absorption of HD vapor and selective conversion to the desired sulfoxide, HDO, at the gas-solid interface.
ABSTRACT
BACKGROUND: Inadequate pain reduction during anesthetic injection is a significant medical and surgical problem. Vibratory distraction reduces this pain; however, there are minimal data identifying those who respond best. OBJECTIVE: To quantify analgesia from vibration before anesthetic injection. MATERIALS AND METHODS: In this partially blinded, single-institution trial, adult participants were randomized to intervention (vibratory anesthetic device, VAD ON) or placebo (VAD OFF). Pain was assessed using the 11-point numeric rating scale (NRS). Relative reduction in NRS between VAD OFF and ON was used to identify minimum clinically important and substantially clinically important difference in pain. RESULTS: One hundred one tested sites from 87 subjects were assessed. Sixty-three percent were men with a median age of 66 years. From univariate analysis, males, subjects aged <60, and head and neck (HN) treated subjects had a significant reduction in NRS (p < .05). Multivariate analysis identified NRS reductions in females <60 (p = .012), males ≥70 (p = .002), females and males treated on HN (p = .048 and p = .035, respectively), and males ≥70 treated on HN (p = .012). Substantially clinically important difference (≥57% NRS reduction) included subjects <60, females <70, HN treatment aged 60 to 69, males ≥70, and females treated on HN. CONCLUSION: Vibratory anesthetic device reduces pain during anesthetic injection, primarily for HN treatments and older male subjects.
