Biomimetic Optical-Filter Sensor System for Discrimination of Infrared Chemical Signatures Against a Cold Sky Background.

Passive infrared (IR) systems enable rapid detection of chemical vapors but are limited by size, weight, cost, and power. Previously, the authors reported a novel passive sensor that utilizes multiple IR filter/detector combinations to discriminate between different chemical vapors based on their unique IR absorption spectra in the same manner the human eye uses to generate colors. This approach enables a very small, compact, and low-power sensor system with the capability to discriminate between chemical vapors of interest and background chemicals. All previous work showed the capability of this sensor system in discriminating chemical vapors against a hot blackbody in a laboratory environment. Now the authors demonstrate the ability of this sensor system to discriminate between the chemical vapor agent simulant dimethyl methylphosphonate and ethanol against the cold sky in an outdoor environment.

Intralesional curettage and surgical adjuvants in the treatment of giant cell tumor of bone: meta-analysis and systematic review.

BACKGROUND: The ideal treatment for giant cell tumor of bone (GCTB) is still controversial. Various surgical adjuvants have been introduced following intralesional curettage to improve local control rates. However, findings from relevant studies are inconsistent, and no consensus has been reached. The purpose of this study is to determine what intraoperative adjuvant is effective in decreasing the recurrence of GCTB. METHODS: We performed a systematic review and meta-analysis of articles published in the PubMed and Embase electronic databases which assessed the recurrence rate of GCTB following intralesional curettage with or without various surgical adjuvants. Two authors independently evaluated all publications. Meta-analysis was performed with Stata/MP (Version 17.0, StataCorp LLC, TX, USA) and Review Manager (RevMan, Version 5.4.1, The Cochrane Collaboration, 2020). Pooled risk ratio (RR) was used for analysis, with P values less than 0.05 considered statistically significant. RESULTS: Twenty-four studies involving 2,579 patients were included in this analysis. The overall recurrence rates for patients treated with or without high-speed burring (HSB) are 11.9% (26/218) and 47.7% (92/193), respectively. The pooled RR for tumor recurrence is 0.33 (95% CI: 0.22 to 0.49, P<0.001). In the meanwhile, the overall recurrence rates for patients treated with or without chemical adjuvants are 23.5% (77/328) and 26.1% (73/280), respectively, with a pooled RR of 0.84 (95% CI: 0.63 to 1.10, P=0.89). Additionally, the overall recurrence rates for patients treated with or without polymethyl methacrylate (PMMA) are 20.4% (205/1,006) and 33.4% (314/939), respectively, with a pooled RR of 0.59 (95% CI: 0.50 to 0.69, P<0.001). CONCLUSIONS: Intraoperative application of HSB or PMMA has an additional antitumor effect, while the use of phenol or H2O2 fails to make any significant difference (PROSPERO: CRD42022344262).

Phosgene Toxicity Clinical Manifestations and Treatment: A Systematic Review.

Exposure to phosgene, a colourless poisonous gas, can lead to various health issues including eye irritation, a dry and burning throat, vomiting, coughing, the production of foamy sputum, difficulty in breathing, and chest pain. This systematic review aims to provide a comprehensive overview of the clinical manifestations and treatment of phosgene toxicity by systematically analyzing available literature. The search was carried out on various scientific online databases to include related studies based on inclusion and exclusion criteria with the use of PRISMA guidelines. The quality of the studies was assessed using the Mixed Methods Appraisal Tool (MMAT). Thirteen articles were included in this study after the screening process. Inhalation was found to be the primary health problem of phosgene exposure with respiratory symptoms such as coughing and dyspnea. Chest pain and pulmonary oedema were also observed in some cases. Furthermore, pulmonary crackle was the most common reported physical examination. Beyond respiratory tract health issues, other organs involvements such as cardiac, skin, eye, and renal were also reported in some studies. The symptoms can occur within minutes to hours after exposure, and the severity of symptoms depends on the amount of inhaled phosgene. The findings showed that bronchodilators can alleviate symptoms of bronchoconstriction caused by phosgene. Oxygen therapy is essential for restoring oxygen levels and improving respiratory function in cases of hypoxemia. In severe cases, endotracheal intubation and invasive mechanical ventilation are used for artificial respiration, along with the removal of tracheal secretions and pulmonary oedema fluid through suctioning as crucial components of supportive therapy.

On the dispersion of a light chemical agent in a semi-closed environment. A theoretical study.

Chemical events have significant public health and emergency preparedness consequences; therefore, crisis response planning is of outmost importance. The dispersion of a chemical agent in an indoor environment, near the so-called "human breathing zone" can cause harmful effects to its occupants. The present study examines the dispersion of ammonia (NH3), i.e., a lighter than air, colorless, highly irritating gas with a suffocating odor, in an office. For that, the turbulent flow of NH3 under the influence of the indoor air's circulation has been simulated, using a Computational Fluid Dynamics model, i.e., the Realizable k-e model. On the whole, the study provides estimation and of the NH3 levels in the office, mainly up to the human breathing zone, as well as evaluation of the natural ventilation's contribution in the decongestion and decontamination of indoor air.•The 3D geometric model of the office was created, taking under consideration the office's structure, the equipment's layout, the openings' positions as well as any other object that could act as an obstacle to the agent's flow.•The domain's 3D Computational Mesh was created and grid independence tests were performed, in order to secure the solution's independence from the grid.•The chemical agent's flow was simulated and the results were compared to the IDLH index and the AEGLs set for ammonia.

Recent advances and future challenges of the starch-based bio-composites for engineering applications.

Starch is regarded as one of the most promising sustainable materials due to its abundant yield and excellent biodegradability. From the perspective of practical engineering applications, this paper systematically describes the development of starch-based bio-composites in the past decade. Packaging properties, processing characteristics, and current challenges for the efficient processing of starch-based bio-composites are reviewed in industrial packaging. Green coatings, binders, adsorbents, flocculants, flame retardants, and emulsifiers are used as examples to illustrate the versatility of starch-based bio-composites in chemical agent applications. In addition, the work compares the application of starch-based bio-composites in conventional spinning with emerging spinning technologies and describes the challenges of electrostatic spinning for preparing nanoscale starch-based fibers. In terms of flexible electronics, the starch-based bio-composites are regard as a solid polymer electrolyte and easily modified porous material. Moreover, we describe the applications of the starch-based gels in tissue engineering, controlled drug release, and medical dressings. Finally, the theoretical input and technical guidance in the advanced sustainable engineering application of the starch-based bio-composites are provided in the work.

Metal Ions and Chemical Modification Reagents Inhibit the Enzymatic Activity of Lecithin-Dependent Hemolysin from Vibrio parahaemolyticus.

Lecithin-dependent thermolabile hemolysin (LDH) is a virulence factor excreted by Vibrio parahaemolyticus, a marine bacterium that causes important losses in shrimp farming. In this study, the function of LDH was investigated through its inhibition by metal ions (Mg2+, Ca2+, Mn2+, Co2+, Ni2+ and Cu2+) and chemical modification reagents: ß-mercaptoethanol (ßME), phenylmethylsulfonyl fluoride (PMSF) and diethyl pyrocarbonate (DEPC). LDH was expressed in the Escherichia coli strain BL-21, purified under denaturing conditions, and the enzymatic activity was evaluated. Cu2+, Ni2+, Co2+ and Ca2+ at 1 mmol/L inhibited the LDH esterase activity by 20−95%, while Mg2+ and Mn2+ slightly increased its activity. Additionally, PMSF and DEPC at 1 mmol/L inhibited the enzymatic activity by 40% and 80%, respectively. Dose-response analysis showed that DEPC was the best-evaluated inhibitor (IC50 = 0.082 mmol/L), followed by Cu2+ > Co2+ > Ni2+ and PMSF (IC50 = 0.146−1.5 mmol/L). Multiple sequence alignment of LDH of V. parahaemolyticus against other Vibrio species showed that LDH has well-conserved GDSL and SGNH motifs, characteristic of the hydrolase/esterase superfamily. Additionally, the homology model showed that the conserved catalytic triad His-Ser-Asp was in the LDH active site. Our results showed that the enzymatic activity of LDH from V. parahaemolyticus was modulated by metal ions and chemical modification, which could be related to the interaction with catalytic amino acid residues such as Ser153 and/or His 393.

Risks and new challenges in the food chain: Viral contamination and decontamination from a global perspective, guidelines, and cleaning.

Even during the continuing world pandemic of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), consumers remain exposed to the risk of getting infected by existing, emerging, or re-emerging foodborne and waterborne viruses. SARS-CoV-2 is different in that it is transmitted directly via the airborne route (droplets and aerosols) or indirect contact (surfaces contaminated with SARS-CoV-2). International food and health organizations and national regulatory bodies have provided guidance to protect individuals active in food premises from potential occupational exposure to SARS-CoV-2, and have recommended chemicals effective in controlling the virus. Additionally, to exclude transmission of foodborne and waterborne viruses, hygiene practices to remove viral contaminants from surfaces are applied in different stages of the food chain (e.g., food plants, food distribution, storage, retail sector, etc.), while new and enhanced measures effective in the control of all types of viruses are under development. This comprehensive review aims to analyze and compare efficacies of existing cleaning practices currently used in the food industry to remove pathogenic viruses from air, nonfood, and food contact surfaces, as well as from food surfaces. In addition, the classification, modes of transmission, and survival of food and waterborne viruses, as well as SARS-CoV-2 will be presented. The international guidelines and national regulations are summarized in terms of virucidal chemical agents and their applications.

Mechanisms modulating the activities of intestinal stem cells upon radiation or chemical agent exposure.

Intestinal stem cells (ISCs) are essential for the regeneration of intestinal cells upon radiation or chemical agent damage. As for radiation-induced damage, the expression of AIM2, YAP, TLR3, PUMA or BVES can aggravate ISCs depletion, while the stimulation of TLR5, HGF/MET signaling, Ass1 gene, Slit/Robo signaling facilitate the radio-resistance of ISCs. Upon chemical agent treatment, the activation of TRAIL or p53/PUMA pathway exacerbate injury on ISCs, while the increased levels of IL-22, ß-arrestin1 can ease the damage. The transformation between reserve ISCs (rISCs) maintaining quiescent states and active ISCs (aISCs) that are highly proliferative has obtained much attention in recent years, in which ISCs expressing high levels of Hopx, Bmi1, mTert, Krt19 or Lrig1 are resistant to radiation injury, and SOX9, MSI2, clusterin, URI are essential for rISCs maintenance. The differentiated cells like Paneth cells and enteroendocrine cells can also obtain stemness driven by radiation injury mediated by Wnt or Notch signaling. Besides, Mex3a-expressed ISCs can survive and then proliferate into intestinal epithelial cells upon chemical agent damage. In addition, the modulation of symbiotic microbes harboring gastrointestinal (GI) tract is also a promising strategy to protect ISCs against radiation damage. Overall, the strategies targeting mechanisms modulating ISCs activities are conducive to alleviating GI injury of patients receiving chemoradiotherapy or victims of nuclear or chemical accident.

An Effective Baseline Correction Algorithm Using Broad Gaussian Vectors for Chemical Agent Detection with Known Raman Signature Spectra.

Raman spectroscopy, which analyzes a Raman scattering spectrum of a target, has emerged as a key technology for non-contact chemical agent (CA) detection. Many CA detection algorithms based on Raman spectroscopy have been studied. However, the baseline, which is caused by fluorescence generated when measuring the Raman scattering spectrum, degrades the performance of CA detection algorithms. Therefore, we propose a baseline correction algorithm that removes the baseline, while minimizing the distortion of the Raman scattering spectrum. Assuming that the baseline is a linear combination of broad Gaussian vectors, we model the measured spectrum as a linear combination of broad Gaussian vectors, bases of background materials and the reference spectra of target CAs. Then, we estimate the baseline and Raman scattering spectrum together using the least squares method. Design parameters of the broad Gaussian vectors are discussed. The proposed algorithm requires reference spectra of target CAs and the background basis matrix. Such prior information can be provided when applying the CA detection algorithm. Via the experiment with real CA spectra measured by the Raman spectrometer, we show that the proposed baseline correction algorithm is more effective for removing the baseline and improving the detection performance, than conventional baseline correction algorithms.

Impaired exercise capacity in electrostatic polyester powder paint workers.

PURPOSE: Limited number of studies investigated the effects of Electrostatic powder paints (EPP) on human health. We investigated the effects of EPP exposure on lung function, exercise capacity, and quality of life, and the factors determining exercise capacity in EPP workers. METHODS: Fifty-four male EPP workers and 54 age-matched healthy male individuals (control group) were included. Lung function and respiratory muscle strength were measured. The lower limit of normal (LLN) cut-points for FEV1 and FEV1/FVC were calculated. An EPT was used to evaluate bronchial hyperactivity. The handgrip and quadriceps muscle strength were evaluated using a hand-held dynamometer. An ISWT was used to determine exercise capacity. The physical activity level was questioned using the IPAQ. The SGRQ and NHP were used to assessing respiratory specific and general quality of life, respectively. RESULTS: Duration of work, FEV1, MIP, handgrip strength, and ISWT distance were significantly lower, and the change in FEV1 after EPT and %HRmax were significantly higher in the EPP group compared to the control group (p < 0.05). There were no subjects with a < LLN for FEV1 and FEV1/FVC in both groups. In the EPP group, ISWT distance was significantly related to age, height, duration of work, FEV1, change in FEV1 after EPT, MIP, MEP, handgrip strength, IPAQ, SGRQ, and NHP total scores (p < 0.05). The change in FEV1 after EPT, MIP, and duration of work explained % 62 of the variance in the ISWT distance (p < 0.001). CONCLUSIONS: Changes in lung function based on LLN for the FEV1 and FEV1/FVC were not clinically relevant in EPP workers. Exercise capacity is impaired in EPP workers. Degree of exercise-induced bronchospasm, inspiratory muscle strength, and duration of work are the determinants of exercise capacity in EPP workers.

Eficácia de um produto à base de oxigênio ativo no tratamento não cirúrgico da Mucosite peri-implantar / Efficacy of an active oxygen-based product in the non-surgical treatment of peri-implant mucositis

A mucosite peri-implantar é uma condição inflamatória sem perda de tecido ósseo, que ocorre nos tecidos moles ao redor do implante. O tratamento não-cirúrgico combina a terapia básica associada ou não ao uso de agentes químicos. O objetivo desse estudo foi avaliar a eficácia do oxigênio ativo (Bluem®) como coadjuvante químico no tratamento não-cirúrgico da mucosite peri­implantar em um protocolo de tratamento não­cirúrgico. Sendo assim, 20 implantes foram tratados, 9 no grupo teste (Bluem®) e 11 no grupo controle (placebo), em indivíduos reabilitados com implantes. Desta forma, os pacientes foram divididos aleatoriamente em grupo teste e grupo controle. Os parâmetros clínicos peri-implantares de índice de placa visível (IPV), índice de sangramento gengival (ISG), profundidade de sondagem (PS), sangramento à sondagem (SS) e mucosa ceratinizada foram avaliados no baseline e em diferentes períodos após o tratamento. Para análise estatística, foram utilizados os testes de Mann-Whitney, Friedman, Wilcoxon e Exato de Fisher com nível de significância de 5%. Os resultados mostraram que houve diminuição significativamente estatística para: IPV geral (56,81% para 27,27%) e ISG geral (32,95% para 28,41%) do grupo teste; IPV geral (42,86% para 15,18%) e ISG geral (31,25% para 2,32%) do grupo controle; IPV do implante no grupo controle (21,42% para 0%); profundidade de sondagem para o grupo teste (2,83mm para 2mm) e SS para o grupo controle (33,33% para 16,67%). No entanto, não houve diferenças significativas entre os dois grupos quando foram comparados em cada período. Pode-se concluir que o Bluem pode ser utilizado como adjuvante químico no tratamento da mucosite peri-implantar, entretanto a sua real eficácia necessita de estudos adicionais para comprovação científica (AU).

Peri-implant mucositis is an inflammatory condition without loss of bone tissue, which occurs in the soft tissues around the implant. Non-surgical treatment combines basic periodontal therapy with or without the use of chemical agents. The objective of this study was to evaluate the efficacy of the active oxygen (Bluem®) as a chemical adjuvant in the non-surgical treatment of peri-implant mucositis. Twenty implants in 9 patients were ramdomly treated, 9 in the test group (Bluem®) and 11 in the control group (placebo), in individuals rehabilitated with dental implants. Peri-implant clinical parameters of visible plaque index (VPI), gingival bleeding index (GBI), probing depth (PD), bleeding on probing (BOP) and keratinized mucosa were evaluated at baseline and one and six months. For the statistical analysis, Mann-Whitney, Friedman, Wilcoxon and Fisher's Exact tests were used with a significance level of 5%. The results showed that there was a statistical decrease for full mouth VPI (56.81% to 27.27%) and full mouth GBI (32.95% to 28.41%) of the test group; full mouth VPI (42.86% to 15.18%) and full mouth GBI (31.25% to 2.32%) of the control group; Implant VPI in the control group (21.42% to 0%); probing depth for the test group (2.83mm to 2mm) and BOP for the control group (33.33% to 16.67%). However, there were no significant differences between the two groups. It can be concluded that Bluem can be used as a chemical adjuvant in the treatment of peri-implant mucositis (AU).

Superhydrophobic and oleophobic ultra-fine dry chemical agent with higher chemical activity and longer fire-protection.

The re-ignition of pool fires is a common hazard phenomenon in fire extinguishing. Dry chemicals with oleophobicity may solve this problem because powders can float on the oil surface and prevent evaporation of fuel pool. In this research, MAPP (modified ammonium polyphosphate) with superhydrophobicity, oleophobicity, and higher chemical activity is prepared which can quickly quench pool fires and provide longer protection. The activation indexes of MAPP for water, diesel, aviation kerosene and gasoline are 98.5%, 87.4%, 98.7% and 98.4%, respectively. Lower activation energy of MAPP means that it will show higher chemical activity in fire. The fire-extinguishing performance of MAPP is much higher than that of Commercial UDCA (ultra-fine dry chemical agent) during fire experiments. After extinguished by MAPP, the fuel pool is hard to be re-ignited. The significance of this study is to propose a new strategy for preventing the re-ignition of pool fires.

Permeability recovery of damaged water sensitive core using ultrasonic waves.

It is imperative to recover the well productivity lose due to formation damage nearby wellbore during variant well operations. Some indispensable issues in conventional techniques make ultrasonic technology more attractive due to simple, reliable, favorable, cost-effective, and environment friendly nature. This study proposes the independent and combined use of ultrasonic waves and chemical agents for the treatment of already damaged core samples caused by exposure to distilled water. Results elucidate that ultrasonic waves with optimum (20kHz, 1000W) instead of maximum frequency and power worked well in the recovery owing to peristaltic transport caused by matching of natural frequency with acoustic waves frequency. In addition, hundred minutes was investigated as optimum irradiation time which provided ample time span to detach fine loosely suspended particles. However, further irradiation adversely affected the damaged permeability recovery. Moreover, permeability improvement attributes to cavitation due to ultrasonic waves propagation through fluid contained in porous medium and thermal energy generated by three different ways. Eventually, experimental outcomes indicated that maximum (25.3%) damaged permeability recovery was witnessed by applying ultrasonic waves with transducer #2 (20kHz and 1000W) and optimum irradiation timeframe (100min). This recovery was further increased to 45.8% by applying chemical agent and optimum ultrasonic waves simultaneously.

Research on ultrasonic excitation for the removal of drilling fluid plug, paraffin deposition plug, polymer plug and inorganic scale plug for near-well ultrasonic processing technology.

Near-well ultrasonic processing technology attracts more attention due to its simple operation, high adaptability, low cost and no pollution to the formation. Although this technology has been investigated in detail through laboratory experiments and field tests, systematic and intensive researches are absent for certain major aspects, such as whether ultrasonic excitation is better than chemical agent for any plugs removal; whether ultrasound-chemical combination plug removal technology has the best plugs removal effect. In this paper, the comparison of removing drilling fluid plug, paraffin deposition plug, polymer plug and inorganic scale plug using ultrasonic excitation, chemical agent and ultrasound-chemical combination plug removal technology is investigated. Results show that the initial core permeability and ultrasonic frequency play a significant role in plug removal. Ultrasonic excitation and chemical agent have different impact on different plugs. The comparison results show that the effect of removing any plugs using ultrasound-chemicals composite plug removal technology is obviously better than that using ultrasonic excitation or chemical agent alone. Such conclusion proves that ultrasonic excitation and chemical agent can cause synergetic effects.

Comparative clinical evaluation of gallium-aluminum-arsenide diode laser and potassium nitrate in treating dentinal hypersensitivity.

CONTEXT: Dentinal hypersensitivity (DH) is a chronic disorder in which patients report sharp and acute pain to a variety of stimuli. Till date, a standardized procedure to treat DH is missing, though several alternative treatment strategies have been designed, including laser therapies. AIM: The aim of the study was to treat DH with minimum chemical concentration and least laser energy level with longer follow-up period. MATERIALS AND METHODS: One hundred and twenty patients were randomly divided into four groups: (i) Group 1-5% potassium nitrate (KNO3); (ii) Group 2 - gallium-aluminum-arsenide diode laser (62.2 J/cm2, wavelength - 980 nm, noncontact pulse mode, and power wattage - 0.5 W); (iii) Group 3 - combined 5% KNO3 and the diode laser; and (iv) Group 4 - placebo (control). The visual analog scale (VAS) scores were recorded, analyzed, and compared to tactile stimuli, cold water, and air blast tests at different intervals for 6 weeks. RESULTS: Synergistic use of 5% KNO3 and diode laser (Group 3) significantly reduced the DH pain, which was almost negligible after 6th week (97%-99% of the pain was reported to be relieved) and showed promising results than any other studied groups. Further, the diode laser (Group 2) showed better results than 5% KNO3 (Group 1). One-way ANOVA and Bonferroni correction post hoc test revealed the combination of groups with significant differences in the mean VAS scores at the different interval of time (P < 0.01). CONCLUSIONS: Convincingly, the combined application of 5% KNO3 with the diode laser can be recommended for treating DH patients.

The Quality of Life of Mustard Gas Victims: A Systematic Review.

BACKGROUND: Today, a host of veterans who were exposed to mustard gas suffer from substantially poor quality of life (QoL). However, factors that influence these patients' QoL have not been yet scrutinized. QoL is deemed as a crucial construct that demands careful attention during evaluation as well as intervention. The present study aimed to delve into the physical, mental, and social factors that affect the QoL of mustard gas victims. MATERIALS AND METHODS: All the physical, mental, and social parameters that influence the QoL of mustard gas victims were scrutinized through a systematic review. We searched for Persian and English scientific databases, i.e., PubMed, Scopus, and Google Scholar, and national databanks, namely SID, IranMedex, and Magiran to identify studies related to chemical victims conducted up to the end of 2015. Next, the quality of 21 articles and studies were assessed using the checklist of the National Institute of Health (NIH), and subsequently, 13 articles were selected for the stages of data extraction and analysis. RESULTS: Findings revealed that, among the physical factors, coexistence of several medical conditions caused by chemical injury and the severity of the chemical injury had the greatest impact on the QoL of chemically injured veterans. Besides, suffering from psychological and neurological disorders, along with educational level and employment status, were the most influential psychosocial parameters that influenced veterans' QoL. CONCLUSION: The review conducted herein identified the physical and psychosocial factors affecting the QoL of mustard gas victims. In fact, it is the first to present a large collection of descriptive information on QoL contributors in a systematic and orderly fashion.

Acquired Bilateral Longitudinal True Leukonychia in a 35-year-old Woman.

Acquired bilateral longitudinal true leukonychia is a rare disorder. We present a case of a 35-year-old healthy woman presented with this unusual and rare manifestation. She mentioned a history of unprotected exposure to detergents and bleaching chemical agents. Considering her low zinc level, she was prescribed with zinc capsules and recommended to avoid chemical substances for 6 months. During bimonthly follow-up, her zinc level turned normal, and leukonychia subsequently disappeared. Bilateral longitudinal true leukonychia in the nails due to zinc deficiency and exposure to chemical substances has not been reported previously. Direct and indirect effects of chemical substances on matrix and the effect of zinc deficiency on healing process should be considered in these cases.

Selection of non-steroidal anti-inflammatory drug and treatment regimen for sulfur mustard-induced cutaneous lesions.

The inflammatory process plays an important role in sulfur mustard (HD) injury and HD pathogenesis, suggesting that anti-inflammatory treatments applied as soon as possible following HD injury may reduce tissue damage and accelerate healing. This study used the HD dermal weanling swine model to investigate the efficacy of two non-steroidal anti-inflammatory drugs, capsaicin and diclofenac, when applied in combination with the steroid, clobetasol. The therapeutic regimen was also investigated with respect to initiation of treatment post-exposure, frequency and duration. Yorkshire-cross pigs were randomly assigned to experimental groups, corresponding to all combinations of treatment (capsaicin with clobetasol or diclofenac with clobetasol), onset time (1, 2 or 4 h post-exposure), treatment duration (1, 3 or 5 days) and frequency of applications (2, 3 or 4 per day). For each animal, two sites on the ventral abdomen were exposed to 400 µL of neat HD for 8 min to achieve superficial dermal (SD) lesions and two sites were exposed to 400 µL neat HD for 30 min to achieve deep dermal (DD) lesions. Each treatment regimen was tested against a SD and a DD injury. Untreated SD and DD lesion sites served as within-animal controls. Assessments, up to one week post-challenge, included digital photographs, clinical assessments (lesion size measurements and modified Draize scoring), transepidermal water loss (TEWL), reflectance colorimetry and histopathologic evaluations that included an estimate for depth of injury and wound healing parameters. Diclofenac plus clobetasol treatment resulted in significant reductions in lesion contracture and modified Draize scores, increased barrier function (decreased TEWL), and increased healing as determined by histopathology for both SD and DD injury when compared with untreated sites and sites treated with capsaicin plus clobetasol. An increased duration of treatment from 1 to 5 days was most commonly associated with decreased clinical assessment and histopathological severity scores. Therefore, a combination of diclofenac and clobetasol application, when administered for at least five days, shows promise in ameliorating HD-induced lesions.

Cutaneous Manifestations of Potential Chemical, Biological, and Radiological Agents and Their Clinical Management / 대한피부과학회지

The level of terrorist threats using chemical, biological, and radiological agents has been continuously increasing, and it is an undeniable truth that these agents are actually in use today. The fact that most chemical, biological, and radiological agents cause skin-related symptoms, and that the skin symptoms are observed at a relatively early stage of the condition, leads to the conclusion that dermatologists could be the first point of contact for potential victims of these agents. It is highly important that first responders are able to recognize symptoms caused by these agents early and react quickly. Therefore, dermatologists do have a responsibility to take on a role in dealing with chemical, biological, and radiological attacks, and pre-equip themselves with professional knowledge in this field. Among the various types of chemical agents, typical examples of agents causing skin-related symptoms are blistering agents, which lead to bullae and necrosis on the skin. Biological agents are classified from Category A to C according to their respective risk factors. The most dangerous Category A agents include anthrax, smallpox, plague, tularemia, and viral hemorrhagic fever, all of which are known to show characteristic skin-related symptoms. Upon exposure to a certain level of radiation, radiological agents can also lead to erythema on the skin. In this article, we will discuss various characteristics and up-to-date treatment methods of potential chemical, biological, and radiological agents to help dermatologists advance their knowledge in this field.

Cutaneous Manifestations of Potential Chemical, Biological, and Radiological Agents and Their Clinical Management / 대한피부과학회지

The level of terrorist threats using chemical, biological, and radiological agents has been continuously increasing, and it is an undeniable truth that these agents are actually in use today. The fact that most chemical, biological, and radiological agents cause skin-related symptoms, and that the skin symptoms are observed at a relatively early stage of the condition, leads to the conclusion that dermatologists could be the first point of contact for potential victims of these agents. It is highly important that first responders are able to recognize symptoms caused by these agents early and react quickly. Therefore, dermatologists do have a responsibility to take on a role in dealing with chemical, biological, and radiological attacks, and pre-equip themselves with professional knowledge in this field. Among the various types of chemical agents, typical examples of agents causing skin-related symptoms are blistering agents, which lead to bullae and necrosis on the skin. Biological agents are classified from Category A to C according to their respective risk factors. The most dangerous Category A agents include anthrax, smallpox, plague, tularemia, and viral hemorrhagic fever, all of which are known to show characteristic skin-related symptoms. Upon exposure to a certain level of radiation, radiological agents can also lead to erythema on the skin. In this article, we will discuss various characteristics and up-to-date treatment methods of potential chemical, biological, and radiological agents to help dermatologists advance their knowledge in this field.