Les neurotoxiques organophosphorés sont appelés agents chimiques de guerre car ils sont une menace à la fois pour les militaires et pour les populations civiles. La voie percutanée est l’une des principales voies d’entrée pour ces agents, et plus particulièrement pour le VX, très peu volatil. La décontamination des surfaces exposées est alors cruciale afin d’éviter l’intoxication des victimes. En cas d’attentat terroriste, le cuir chevelu humain pourrait être un site préférentiel d’exposition. Cette partie du corps, riche en follicules pileux, pourrait nécessiter des produits et des processus de décontamination adaptés. Ce travail est divisé en 4 parties : 1) Validation d’un modèle de peau in vitro pour le cuir chevelu humain ; 2) Détermination des stratégies de décontamination ; 3) Formulation de nouveaux systèmes de décontamination ; 4) Évaluation de leur efficacité de décontamination. La peau d’oreille de porc est un modèle pertinent pour l’étude de la pénétration percutanée in vitro du VX à travers le cuir chevelu humain. La peau de dessus de tête de porc représente un bon modèle de cuir chevelu humain pour l’étude de l’affinité du VX avec la tige pilaire. L’étude de distribution du VX selon différents temps d’exposition a montré que la majorité du toxique reste à la surface de la peau jusqu’à 2h d’exposition. Il est donc intéressant de décontaminer la peau même après 2h d’exposition aux agents chimiques de guerre. Les microémulsions comprenant un actif détoxifiant (oxime) sont les systèmes les plus efficaces car ils pénètrent en profondeur afin de venir détruire le toxique in situ dans la peau. Les poudres et les émulsions de Pickering ont une action de surface et permettent d’extraire le toxique présent à la surface de la peau et dans les couches superficielles. Les résultats de nos études in vitro ont montré que ces formulations sont significativement plus efficaces que la terre à foulon pour une décontamination après 45 min d’exposition au VX / Organophosphorous nerve agents are designed as chemical warfare agent because they represent a threat both for the military and the civilians. Due to its low volatility, VX mainly remains in its liquid form and mostly presents a contamination by skin contact. Decontamination of exposed body surface is therefore crucial to prevent victims' poisoning. In case of terrorist acts, civilian human scalp could be a preferential site of exposure. This body region, rich in hair follicles, may require adapted decontamination products and procedures. The aims of this work are: 1) Validation of a relevant in vitro human scalp skin model; 2) Determination of decontamination strategies; 3) Formulation of new decontamination systems; 4) Evaluation of their decontamination efficacy. Pig ear skin is a relevant model when studying the in vitro percutaneous penetration of VX through human scalp. Pig skull roof skin could be used when studying the affinity of VX for hair. This study has shown that most of the nerve agent remains on the skin surface up to 2h of exposure, which means that it is worth decontaminating even if contamination occurred 2h before. Microemulsions loading a detoxifying agent (oxime) are the most efficient systems because they are able to penetrate deeper into the skin to neutralize the agent in situ. Adsorbing powders and Pickering emulsions could interact with the agent present on the skin surface and in the superficial layers. Our results from the in vitro experiments have demonstrated that these formulations are more efficient than Fuller's earth for skin decontamination after 45 min of VX exposure

This study addressed five key applications of paper spray mass spectrometry (PS-MS): (i) comparative analysis of the microporous substrate with the cellulose-based substrate in drug detection; (ii) detection of more than 190 fentanyl analogs with their fragmentation pattern can be implemented in the future reference for quicker, accurate and sensitive determination; (iii) exploring sweat in a fingerprint to be considered an alternate method to recognize non-invasive markers of metabolites, lipids, narcotics, and explosive residues that can be used in forensic testing applications; (iv) extending and improving better, cost-effective and quick real-time monitoring of the diseased stage using biofluid samples to obtain vastly different lipid information in viral infection such as COVID-19; and (v) mass spectral detection in chemical warfare agent (CWA) stimulant gas exposure with microporous structure absorbency capabilities in air quality monitoring. This novel synthetic material is known as Teslin® (PPG Industries), consisting of a microporous polyolefin single-layered silica matrix, can be used for precise, sensitive, selective, and rapid sample analysis with PS-MS. The Teslin® substrate provided longer activation time for samples and an active signal with a higher concentration of ion formation and mobility compared to cellulose-based papers. Direct analysis of multiple samples showed that, besides being more sensitive to the study and highly efficient with less sample size and spray solvent needed, Teslin® had less interaction with paper source molecules. For less than 60 seconds of processing time, PS-MS can be used as a rapid detection tool, with limited sample preparation requiring less than one microgram of the sample. Overall, the data in this analysis indicate the capacity of the PS-MS as an alternative approach for direct chemical analysis in many applications. Specifically, the waterproof and microporosity characteristics of Teslin® have proven its usefulness in detecting a variety of chemical components in liquid, solid, and gaseous phases without requiring any chemical treatment or substrate alteration.

Thesis (Ph. D.)--Uniformed Services University of the Health Sciences, 2005. / Typescript (photocopy).

Thesis (M.S.)--Uniformed Services University of the Health Sciences, 2005. / Typescript (photocopy).

Kemisk krigföring i form av luftburna gifter har förekommit i många historiska kontexter. Trots att luftburna gifter, som till exempel giftig rök och gas är likartade företeelser, har inte forskare kunnat enas om äldre former av denna krigföring är jämförbar med den moderna. Huvudorsaken är att deras analyser saknar teoretiska perspektiv som belyser hur respektive   kontexts kemiska förutsättningar påverkar krigföringen. Syftet med den här undersökningen är att jämföra ett modernt nyttjande av luftburna gifter, tyskarnas första klorutsläpp vid Ypres 1915 med ett forntida exempel, den moistiska skolans användande av brandrök som gift under århundradena f. Kr. i Kina. För att kringgå tidigare forsknings problem anläggs ett teoretiskt perspektiv. En teori som belyser dynamiken   mellan kemisk krigföring och respektive kulturs föreställningar om och förhållande till miljön. Undersökningen visar att det är relevant att jämföra det moderna användandet av luftburna gifter med användandet i andra historiska kontexter eftersom det sker i liknande taktiska sammanhang och kräver mycket naturkunskap. Samtidigt belyser analysen att kontexten ger krigföringen en viss karaktär. Moisterna försökte nå framgång genom att samordna och   förbättra den process som gjorde det luftburna giftet effektivt samtidigt som de förlitade sig på generalistkunskap. Tyskarna, däremot förlitade sig på ett så effektivt  kemiskt ämne (agens) som möjligt. För denna typ av krigföring nyttjades utpräglade specialister.   Dessutom var relationen till själva giftet annorlunda i de två kontexterna. Moisterna utsatte sig för röken medan tyskarna avskärmade sig helt från klorgasen. Dessa skillnader går att förstå genom att se hur människorna i respektive kontext utnyttjade den för krigföringen relevanta kemin i icke-militära sammanhang. Den tidigare forskningens problem med att diskutera kemisk krigföring blir också tydligt i undersökningen. Problemet beror på att den vetenskapliga disciplinen kemi medför institutioner och begrepp som begränsar synen på användandet av luftburna gifter. Denna insikt tillsammans med undersökningens övriga resultat belyser något som har relevans för dagens hotbild. Luftburna gifter, kan i rätt sammanhang och genom rätt   prioriteringar göras effektiv utan tillgång till modern vetenskap och industri. Detta bör beaktas när hotbilden från aktörer utan egen militärindustri analyseras. / Airborne poison, as a type of chemical warfare, has been used in many historical contexts. Although airborne poison such as toxic smoke and gas are similar phenomena, researchers have not been able to agree if older forms of warfare are comparable to modern. One reason for this is that their respective analysis lacks theoretical perspectives that account for contextual chemical conditions. The purpose of this study is to compare a modern example of the use of airborne poison, the Germans' first chlorine emissions at Ypres in 1915 with an ancient one, the Mohists use of smoke as a poison in ancient China. A theoretical perspective is applied to circumvent the problems of earlier research. This theory focuses on the dynamics between decision-making in chemical warfare and a particular culture's perception of and relationship to the environment. The study shows that it is relevant to compare the modern use of airborne poison with its use in other historical contexts because the weapon occurs in a similar tactical context. Also this type of warfare requires a lot of knowledge of the natural world. At the same time the analysis illustrates that a specific context gives the warfare a certain character. The Mohists tried to achieve success by coordinating and improving the process by which the airborne poison was made effective. Furthermore they relied on generalist knowledge. The Germans, however, relied on having an efficient chemical substance (agent). For this type of warfare they utilized specialists. The human-poison relationship also differed. The Mohist exposed himself to smoke while the German soldier shut himself off completely from the chlorine gas. These differences can be understood by studying how people exploited similar chemistry in a non-military way  in their respective context. The problems that previous research has had in discussing chemical warfare is also made evident. These problems occur because chemistry as a scientific discipline creates institutions and concepts that limit the view of airborne poison as a weapon. This realization, along with results of the survey in general, illustrates something which has relevance in today’s world. Airborne poison can, in the right place and with the right priorities be effective without modern industrial and scientific resources. This should be considered when analyzing political actors lacking a modern military industry.