Type Of Detergent Research Articles

Antiviral Drug Discovery with an Optimized Biochemical Dengue Protease Assay: Improved Predictive Power for Antiviral Efficacy

The viral NS2B-NS3 protease is a promising drug target to combat dengue virus (DENV) and other emerging flaviviruses. The discovery of novel DENV protease inhibitors with antiviral efficacy is hampered by the low predictive power of biochemical assays. We herein present a comparative evaluation of biochemical DENV protease assay conditions and their benchmarking against antiviral efficacy and a protease-specific reporter gene assay. Variations were performed with respect to pH, type of detergent, buffer, and substrate. The revised assay conditions were applied in a medicinal chemistry effort aimed at phenylglycine protease inhibitors. This validation study demonstrated a considerably improved predictive power for antiviral efficacy in comparison to previous approaches. An extensive evaluation of phenylglycine-based DENV protease inhibitors with highly diverse N-terminal caps indicates further development potential in this structural region. Furthermore, the phenylglycine moiety may be less essential than previously assumed, providing a development option towards reduced lipophilicity and thereby an improved pharmacokinetic and toxicity profile.

Multiple intermediates in the detergent-induced fusion of lipid vesicles

Detergent-induced vesicle interactions, critical for applications including virus inactivation, varies according to the detergent type and membrane composition, but the underlying mechanistic details remain underexplored. Here, we use a lipid mixing assay based on Förster resonance energy transfer (FRET), and single-vesicle characterization approaches to identify that sub-micron-sized vesicles are induced to fuse by the non-ionic detergent Triton-X-100. We demonstrate that the process is a multi-step mechanism, characterized by discrete values of FRET efficiency between membrane-embedded fluorophores, and involves permeabilization, vesicle docking, hemi-fusion and full lipid mixing at sub-solubilizing detergent concentrations. We also dissect the kinetics of vesicle fusion to surface-tethered vesicles using a label-free quartz-crystal microbalance with dissipation monitoring approach, opening a platform for biotechnology applications. The presented strategies provide mechanistic insight into the dynamics of vesicle fusion and have implications for applications including drug delivery and sensor development where transport and manipulation of encapsulated cargo is essential.

Simulation and modelling of the detergent corona around the membrane protein MhsT based on SAXS data

For membrane proteins, ab initio modelling based on a single curve of small-angle X-ray scattering (SAXS) is precluded by the presence of detergent molecules bound to the hydrophobic region of the protein. MEMPROT was developed for the modelling of protein–detergent complexes based on the SAXS curve of the complex, and on an a priori representation of the detergent corona by an elliptical semi-torus surrounding the protein. In previous studies, MEMPROT has succeeded in modelling several membrane proteins solubilized in n-dodecyl-β-maltopyranoside (DDM). However, it has never been tested on proteins solubilized in other detergents. To understand whether the geometrical shape currently parametrized in MEMPROT could be applied to a broader catalogue of protein–detergent complexes, here, MEMPROT was used to model the detergent corona around the multi-hydrophobic substrate transporter from Bacillus halodurans solubilized in four different detergents, namely DDM, n-decyl-β-maltopyranoside (DM), 4-cyclohexyl-1-butyl-β-D-maltoside (Cymal4) and decyl-maltose-neopentyl-glycol (DMNG). The study indicates a significant variation in detergent shapes, depending on the type of detergent. The modelling results suggest that the elliptical semi-torus with a circular closure is an excellent approximation for long-tailed detergents (DDM and DM) but leads to a slightly poorer agreement with the data for DMNG and Cymal4, which have a shorter hydrophobic tail, smaller than the half-width of the protein hydrophobic region. Here, for the latter, it is hypothesized that a corona with a flatter closure would be a better shape descriptor.

In Vitro Effects of Chlorhexidine and Isopropyl Alcohol Conditioning Agents on Immediate and Late Bond Strength of Fiber Posts Dentin.

Objectives: This study assessed the effect of chlorhexidine (CHX) and isopropyl alcohol (IA) on immediate and late pushout bond strength (PBS) of fiber posts to dentin. Materials and Methods: In this in vitro study, 54 single-canal premolars were endodontically treated, and randomly assigned to 3 groups (N=18) for root dentin conditioning with distilled water (control), 2% CHX, and 70% IA after post space preparation. Fiber posts were cemented with TheraCem self-adhesive cement, and each group was subdivided into two subgroups (N=9) for PBS measurement immediately after bonding, and after 5000 thermal cycles (5-55°C). The roots were then sectioned, and their PBS was measured. The mode of failure was evaluated under a stereomicroscope at ×40 magnification. Data were analyzed by repeated measures ANOVA and Tukey's test (alpha=0.05). Results: The highest PBS was noted in the IA group (21.12 MPa) after 24 hours and the lowest PBS belonged to the control group after thermocycling (7.48 MPa). The immediate and post-thermocycling PBS were significantly lower in the control group than the CHX group (P<0.05). The PBS in both the control and CHX groups was lower than that in the IA group (P<0.001). Regardless of the type of detergent, a significant reduction in PBS was observed after thermocycling (P<0.003). The PBS significantly decreased from the cervical towards the apical region in all groups (P<0.001). Conclusion: According to the results, application of IA before the self-adhesive cement effectively improved the immediate and late PBS, and was significantly more effective than CHX.

Ecotoxicological Evaluation of Two Types of Commercial Detergents on Radish (Raphanus Sativus) Seeds

This study aimed to evaluate the ecotoxicological effect of commonly used liquid and powder detergents on the parameters of germination capacity, root and hypocotyl growth, germination index, and median lethal dose (LD50) in seeds of Raphanus sativus (radish). Seeds were acclimatized under standardized conditions. Bioassays were prepared from a 50% standard solution, obtaining concentrations of 10;20;30;40;40;50 ppm of both detergents, each bioassay followed the completely randomized block experimental design: four replicates, one positive control, six seeds for 72 hours, ANOVA was implemented using Excel 2019. The germination percentage for the powder detergent (A) was 27.67%, while the liquid (B) did not present problems in the development. The root and hypocotyl inhalation for detergent A was 6.75 and 17.65% and B 38.24% and 50.45%, respectively; the germination index for detergent A and B was 5.80 and 38.24%, respectively. The median lethal dose was only 20.27 mg/L for detergent A. It was possible to establish that the increase in the concentrations of the detergents, decreases the determined parameters, consequent of the detergents with surfactants and sulfactants. Keywords: bioassay, germination, ecotoxigenology, Raphanus sativus, detergents, root elongation. Resumen El objetivo del estudio fue evaluar el efecto ecotoxicológico de los detergentes de uso común líquido y en polvo sobre los parámetros de la capacidad de germinación, crecimiento radicular e hipocótilo, índice de germinación y la dosis letal media (DL50) en semillas de raphanus sativus (rábano). Las semillas fueron aclimatadas en condiciones estandarizadas. Se prepararon bioensayos a partir de una solución patrón del 50%, obteniendo concentraciones de 10;20;30;40;50 ppm de ambos detergentes, cada bioensayo siguió el diseño experimental de bloques completamente al azar: cuatro repeticiones, un control positivo, seis semillas durante 72 horas, se implementó el análisis de varianza ANOVA mediante Excel 2019. El porcentaje de germinación para el detergente en polvo (A) fue de 27, 67%, el líquido (B) no presentó problemas en el desarrollo; la inhibición radicular e hipocótilo para el detergente A fue 6,75 y 17,65% y el B 38,24% y 50,45%, respectivamente; el índice de germinación para el detergente A y B: 5,80 y 38,24%, respectivamente. La Dosis Letal Media solo se presentó en el detergente A fue de 20,27 mg/L. Se logró establecer que el aumento de las concentraciones de los detergentes disminuye los parámetros determinados, consecuente de los detergentes con tensoactivos y surfactantes. Palabras Clave: Bioensayo, germinación, ecotoxigología, Raphanus sativus, detergentes, elongación de las raíces.

Effect of pollutants on the oviposition and embryo development of the invasive snail Physella acuta (Gastropoda: Physidae)

ABSTRACT The varied types of detergent are considered as contaminants in the freshwater environment and interfere with the bio-ecology of macroinvertebrates. Based on this proposition, a study was conducted to examine the impact of detergents and acidic bathroom cleaners on the oviposition and embryo development of the invasive snail Physella acuta (Draparnaud, 1805) (Gastropoda: Physidae). Laboratory-based experiments were carried out to observe the oviposition pattern and embryo development under varied concentrations of commercially available detergent and bathroom cleaner. The invasive snail, P. acuta, breeds throughout the year, and its reproduction positively correlates with shell length. The results of this study implied that the fecundity and hatching rate were reduced and varied with detergent and bathroom cleaner concentrations compared to the control group. Among the treatments, the higher doses of bathroom cleaners impaired the embryo development of P. acuta. The results suggest that the colonization and establishment of the invasive snail P. acuta in the new habitats may be affected by detergent contamination of the freshwater habitats. While the present study aims to provide a link between the detergent and oviposition pattern of the freshwater snail, further studies should be carried out to deduce the long-term effects of the detergents on the population dynamics of P. acuta.

Metabarcoding Analysis of Microorganisms Inside Household Washing Machines in Shanghai, China.

Washing machines are one of the tools that bring great convenience to people's daily lives. However, washing machines that have been used for a long time often develop issues such as odor and mold, which can pose health hazards to consumers. There exists a conspicuous gap in our understanding of the microorganisms that inhabit the inner workings of washing machines. In this study, samples were collected from 22 washing machines in Shanghai, China, including both water eluted from different parts of washing machines and biofilms. Quantitative qualitative analysis was performed using fluorescence PCR quantification, and microbial communities were characterized by high-throughput sequencing (HTS). This showed that the microbial communities in all samples were predominantly composed of bacteria. HTS results showed that in the eluted water samples, the bacteria mainly included Pseudomonas, Enhydrobacter, Brevibacterium, and Acinetobacter. Conversely, in the biofilm samples, Enhydrobacter and Brevibacterium were the predominant bacterial microorganisms. Correlation analysis results revealed that microbial colonies in washing machines were significantly correlated with years of use and the type of detergent used to clean the washing machine. As numerous pathogenic microorganisms can be observed in the results, effective preventive measures and future research are essential to mitigate these health problems and ensure the continued safe use of these household appliances.

The selection of washing machine programs with fuzzy dematel and moora-ratio multi-criteria decision-making methods considering environmental and cost criteria

The washing machine is the prevalent white household equipment in contemporary society. These machines provide consumers with a range of program options that encompass several variables, including temperature and detergent type. Nevertheless, the selection made by individual customers about the washing machine program they opt for carries substantial environmental consequences during the use stage of textile products. According to studies on the life cycle of clothes, it has been established that the use stage, following the extraction of raw materials, exerts the most substantial influence on environmental impacts. The objective of this research is to assess the washing machine programs provided by the manufacturer through the application of a comprehensive systematic approach for analysis. The evaluation of scenarios for washing machine programs was conducted using the MOORA-Ratio multi-criteria decision-making process. This evaluation considered various parameters, including environmental impact and cost. The life cycle assessment methodology was employed to quantify the environmental impact of the specified criteria. Based on the comprehensive study conducted by integrating criteria across numerous dimensions, it has been determined that the most favorable scenario wass scenario 1, which was developed for the Cotton 20 C program. The primary objective of this research endeavor is to fill a significant need in the current body of literature by undertaking a comprehensive review of washing machine programs that have not been previously recorded. This study employs a comprehensive methodology to investigate the environmental and economic implications linked to these activities, with the objective of delivering significant insights to producers and users.

Three-Dimensional-Printed Photocatalytic Sponges Decorated with Mn-Doped ZnO Nanoparticles.

The present work reports on the fabrication of high-density polyethylene sponges, decorated with Mn-doped ZnO nanostructures. The sponges were developed utilizing three-dimensional printing technology, while Mn-doped ZnO nanostructures, with varying doping levels, were grown at mild temperatures. The nanostructures were fully characterized by means of scanning electron microscopy, X-ray diffraction, and Raman spectroscopy, revealing the existence of Mn doping. Moreover, their photocatalytic properties were investigated using the degradation/decolorization of a commercially available liquid laundry detergent, based on synthetic, less foaming ingredients, under UV irradiation. The Mn-doped ZnO nanostructures show better photocatalytic activity at higher doping levels. This study demonstrates that it is possible to achieve the adequate degradation of a typical detergent solution in water by means of low-cost and environmentally friendly approaches, while Mn-doped ZnO/HDPE nanostructures are good candidates for real environmental applications.

Solvents and detergents compatible with enzyme kinetic studies of cholinesterases

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are enzymes that serve a wide range of physiological functions including the hydrolysis of the neurotransmitter acetylcholine and several other xenobiotics. The development of inhibitors for these enzymes has been the focus for the treatment of several conditions, such as Alzheimer's disease. Novel chemical entities are evaluated as potential inhibitors of AChE and BChE using enzyme kinetics. A common issue encountered in these studies is low aqueous solubility of the possible inhibitor. Additives such as cosolvents or detergents can be included in these studies improve the aqueous solubility. Typical cosolvents include acetonitrile or dimethyl sulfoxide while typical detergents include Polysorbate 20 (Tween 20) or 3-((3-cholamidopropyl) dimethylammonio)-1-propanesulfonate (CHAPS). When solubility is not improved, these molecules are often not evaluated further. To address this issue eleven cosolvents and six detergents that could facilitate aqueous solubility were evaluated to understand how they would affect cholinesterase enzymes using Ellman's assay. These studies show that propylene glycol, acetonitrile, methanol, Tween 20, Polysorbate 80 (Tween 80), polyoxyethylene 23 lauryl ether (Brij 35) and polyoxyethylene 10 oleoyl ether (Brij 96v) have the least inhibitory effects towards cholinesterase activity. It is concluded that these cosolvents and detergents should be considered as solubilizing agents for evaluation of potential cholinesterase inhibitors with low aqueous solubility.

Electrochemical degradation of surfactants in domestic wastewater using a DiaClean® cell equipped with a boron-doped diamond electrode.

Treating domestic wastewater has become more and more complicated due to the high content of different types of detergents. In this context, advanced electro-oxidation (AEO) has become a powerful tool for complex wastewater remediation. The electrochemical degradation of surfactants present in domestic wastewater was carried out using a DiaClean® cell in a recirculation system equipped with boron-doped diamond (BDD) as the anode and stainless steel as the cathode. The effect of recirculation flow (1.5, 4.0 and 7.0Lmin-1) and the applied current density (j = 7, 14, 20, 30, 40, and 50mAcm-2) was studied. The degradation was followed by the concentration of surfactants, chemical oxygen demand (COD), and turbidity. pH value, conductivity, temperature, sulfates, nitrates, phosphates, and chlorides were also evaluated. Toxicity assays were studied through evaluating Chlorella sp. performance at 0, 3, and 7h of treatment. Finally, the mineralization was followed by total organic carbon (TOC) under optimal operating conditions. The results showed that applying j = 14mAcm-2 and a flow rate of 1.5Lmin-1 during 7h of electrolysis were the best conditions for the efficient mineralization of wastewater, achieving the removal of 64.7% of surfactants, 48.7% of COD, 24.9% of turbidity, and 44.9% of mineralization analyzed by the removal of TOC. The toxicity assays showed that Chlorella microalgae were unable to grow in AEO-treated wastewater (cellular density: 0 × 104 cellsml-1 after 3- and 7-h treatments). Finally, the energy consumption was analyzed, and the operating cost of 1.40 USD m-3 was calculated. Therefore, this technology allows for the degradation of complex and stable molecules such as surfactants in real and complex wastewater, if toxicity is not taken into account.

Isolation and molecular identification of washing machine bacteria and study of the effect of some detergents on their growth

This study aimed to isolate, molecular identify, and evaluate the antimicrobial activity of the three commercial types of household detergents; Persil (P), Arial (A), and Peros (Pe) in both forms of gel liquid and (Tate ) powder and antibiotics susceptibility test to assessed against isolates from used washing machines in Mosul city/ Iraq. A total of 46 bacterial isolates were isolated. Five isolates were designated as Kh-Am1, Kh-Am4 from the Drum part, Kh-Am3, Kh-Am6 from the Rubber door seal part and Kh-Am5 from Drain dictum; these isolates were selected for molecular identification by 16S rRNA. The 16S rRNA gene of Kh-Am1, Kh-Am3, Kh-Am4, Kh-Am5 and Kh-Am6. The disc agar diffusion method was adopted for each selected isolate using stock and diluted concentrations. After incubation at 37ₒC for 24 hours, inhibition of Aerea was recorded. The results showed that the powder and gel form detergent stock solution has more inhibitory efficacy for the assayed isolates than dilutions. Susceptibility to antibiotics assay revealed that almost all the selected isolates were resistant. Even though infectious strains were not found, opportunistic pathogens were detected. However, because many bacteria have been detected in wash water, washing items at home with it may result in microbial contamination. Keywords: Washing machine bacteria, Washing machine environment, Detergents effect on bacteria, Antibiotic Susceptibility of washing machine bacteria.

Optimization of the Hemolysis Assay for the Assessment of Cytotoxicity.

In vitro determination of hemolytic properties is a common and important method for preliminary evaluation of cytotoxicity of chemicals, drugs, or any blood-contacting medical device or material. The method itself is relatively straightforward, however, protocols used in the literature vary substantially. This leads to significant difficulties both in interpreting and in comparing the obtained values. Here, we examine how the different variables used under different experimental setups may affect the outcome of this assay. We find that certain key parameters affect the hemolysis measurements in a critical manner. The hemolytic effect of compounds tested here varied up to fourfold depending on the species of the blood source. The use of different types of detergents used for generating positive control samples (i.e., 100% hemolysis) produced up to 2.7-fold differences in the calculated hemolysis ratios. Furthermore, we find an expected, but substantial, increase in the number of hemolyzed erythrocytes with increasing erythrocyte concentration and with prolonged incubation time, which in turn affects the calculated hemolysis ratios. Based on our findings we propose an optimized protocol in an attempt to standardize future hemolysis studies.

Contribution of household dishwashing to microplastic pollution

At household level, clothes washing has been recognised as an emitter of microplastics (MPs) into the environment and it is supposed that dishwashing is also a source of MPs, although little attention has been paid so far. In this work, the emission of MPs released from dishwashing procedures at household level has been studied. The effect of different parameters such as time, temperature and type of detergent has been analysed. In addition, the MP content of tap water has been evaluated in order to determine its contribution to the MPs in dishwasher effluent. Results showed that when the dishwasher was operated empty with a pre-wash programme (15 min and room water temperature), between 207 and 427 MPs were released per load (3 L), whereas this value increased notably with an intensive programme (164 min and water at 70 °C) (1025–1370 MPs per load, 15 L), which highlighted the effect of temperature and time on MP release. Additionally, when a polypropylene lunch box was washed, the number of MPs released increased by 14 ± 3 MPs and 166 ± 12 MPs of total. Finally, the influence of the use of detergent with the dishwasher empty and containing lunch boxes has been studied. With detergent, 35–54% more MPs were released from dishwasher accessories, whereas no additional release took place from lunch boxes. This work shows for the first time the important contribution of domestic dishwashing to MP pollution and the environmental benefits of using more environmentally friendly materials in both dishwashing machine accessories and food utensils.

Microplastic Fiber Release by Laundry: A Comparative Study of Hand-Washing and Machine-Washing

Microplastic fiber (MPF) shed during textile washing is one of the important sources of microplastics in the aquatic environment. There have been many studies on MPF release by machine-washing of textiles. However, traditional hand-washing still remains very common in many regions around the world. To date, MPF release from hand-washing remains to be less studied and understood. In this study, we examined its release characteristics as a function of various factors. Besides, we also evaluated a machine-washing experiment to compare the differences in MPF release by these two washing modes. The experimental results indicated that the mean fiber length of MPFs by hand-washing (258 μm) was generally longer than those by machine-washing (155 μm); the mean numbers of MPFs released from the hand-washing and machine-washing were 1853 and 23,723 n/piece, and their corresponding mean mass of MPFs were 37.84 and 222.84 mg fiber/kg textile. Moreover, the MPF initially decreased in number and mass and then stabilized gradually with sequential washings. Among all of the variables tested, temperature, detergent type, washing time, and water volume have no significant effect on MPF release, while the use of detergent (<1.5 g/L), soaking time (<2 h), and the use of washboard increase MPF release.

Develop an optimal daily washing care for technical jacket by balancing washing efficiency and functional degradation

In order to reduce the functional degradation caused by improper daily washing-care and prolong the service life of technical jacket, the relationship between the daily washing conditions and functional degradation in the wearing performance of technical jacket (waterproof, windproof, warmth retention) was quantitatively investigated with the help of hydrostatic pressure, surface contact angle, air permeability, warmth retention, and scanning electron microscopy (SEM) of technical jacket after different daily washing conditions. Results showed that no matter what kind of washing modes, washing parameters, type and dosage of detergent, the wearing performance of technical jacket after washing were subjected to decrease compared with pre-washing. Additionally, it was also found that the effects of washing modes, type of detergents and washing parameters on the wearing performance of the technical jacket were significant, instead of the dosage of detergents. This indicates it was possible ways to minimize functional degradation by setting optimal washing conditions (washing parameters, washing mode, types and dosage of detergent). Balancing considerations of functional degradation and washing efficiency, the washing combination of mechanical agitation + micro-nano bubbles), type of detergent (neutral liquid detergent), dosage of detergent (3 g/L), water temperature (20°C), main washing bath ratio (1:10), main washing speed (15 rpm), main washing time (20 min), rinsing speed (30 rpm), rinsing cycles (2), belonged to the optimal washing combination in this study of washing condition. The results were of practical significance to guide manufacturers of washing machine to develop optimal daily washing produce for outdoor clothing, especially technical jacket.

Corrosion resistance of stainless-steel surgical tools in enzymatic and alkaline detergent

Metallic surgical instruments are subject to corrosion, which can be accelerated when there is an attack on the passive layer formed on the stainless-steel surfaces. Corrosion can create defects on the metal surface, which can retain residues and promote microbiological growth, leading to infections in surgeries and contamination of medical devices. Since these applications require a high degree of cleaning and sterilization, such items undergo recurrent cleaning cycles using water and detergents. This study aims to test two types of detergents, alkaline and enzymatic, comparing their effects on corrosion resistance of AISI 304 L, 316 L and 420 stainless steels (SS), commonly used in surgical instruments. The electrochemical impedance spectroscopy, and cyclic polarization tests were used to evaluate the corrosion resistance of stainless steels in detergents. Scanning electron microscopy was used to study the morphology of the steel surfaces after corrosion tests. The AISI 304 L steel showed the highest corrosion resistance in the enzymatic medium among the three stainless steels tested. The AISI 316 L stainless steel had an intermediate behavior in enzymatic medium, and lower impedance when immersed in alkaline detergent, while the AISI 420 steel showed deeper corrosion marks on its surface in alkaline medium when compared to the enzymatic solution. The enzymatic detergent is the less aggressive medium to the steels, and the AISI 304 L SS was the most corrosion resistant in alkaline and enzymatic detergents. • The corrosion resistance of stainless steels used in surgical instruments was evaluated • The aggressiveness to the steel of alkaline and enzymatic detergents was studied • The electrochemical impedance spectroscopy and cyclic polarization were used • The AISI 304 steel showed the highest corrosion resistance in enzymatic medium • The enzymatic detergent is the less aggressive medium to the steels

Effectiveness of dermal cleaning interventions for reducing firefighters’ exposures to PAHs and genotoxins

Firefighters are exposed to carcinogenic and mutagenic combustion emissions, including polycyclic aromatic hydrocarbons (PAHs). Fire service and firefighter cancer advocacy groups recommend skin cleaning using wipes or washing with detergent and water after exposure to smoke, although these strategies have not been proven to reduce exposures to harmful combustion products such as PAHs. This study assessed dermal decontamination methods to reduce PAH exposures by firefighters participating in live fire training scenarios. Study participants (n = 88) were randomly assigned to an intervention group (i.e., two types of commercial skin wipes, detergent and water, or a control group who did not use any skin decontamination). PAHs were measured in personal air (during the fire) and dermal wipe samples (before and after fire suppression and after dermal decontamination). PAH metabolites and mutagenicity were measured in urine samples before and after fire suppression. Airborne PAH concentrations during the fire ranged between 200 and 3,970 μg/m3 (mean = 759 μg/m3, SD = 685 μg/m3). Firefighters had higher total PAHs and high-molecular-weight PAHs on their skin after the fire compared to before (1.3- and 2.2-fold, respectively, p < 0.01). Urinary PAH metabolites increased significantly following exposure to the training fires by 1.7 to 2.2-fold (depending on the metabolite, p < 0.001). Urinary mutagenicity did not differ significantly between pre- and post-fire for any of the decontamination methods. Detergent and water was the only intervention that removed a significant amount of total PAHs from the skin (0.72 ng/cm2 preintervention vs. 0.38 ng/cm2 postintervention, p < 0.01). However, fold changes in urinary PAH metabolites (i.e., pre- vs. post-exposure levels) did not differ among any of the dermal decontamination methods or the control group. These data suggest that despite on-site attempts to remove PAHs from firefighters’ skin, the examined interventions did not reduce the internal dose of PAHs. Future work should investigate preventing initial exposure using other interventions, such as improved personal protective equipment.

Radioactive decontamination in low-temperature environments by using a novel high-strength strippable coating

Accidents involving nuclear leakage and radioactive source diffusion will result in a substantial amount of radioactive pollution, posing a threat to the world's environment as well as human safety. To get rid of the pollution, this work describes a new type of strippable detergent coating designed to remove radioactive contamination, especially in low-temperature conditions. In situ polymerization was employed to make EC/PUA/PVAc detergent from degradable ethyl cellulose (EC), tea polyphenols (TP), and polyvinyl acetate (PVAc), and polytetramethylene ether glycol bis-para-aminobenzoate (P1000). The film-forming performance, decontamination efficiency, and mechanical properties of the decontamination coating formed by the detergent were studied. Designed to work in a low-temperature environment, the detergent can be sprayed and peeled to remove surface radioactive staining. A universal material testing machine was used to assess the low-temperature rheometry, SEM, EDX, FT-IR, and other variables and to characterize the decontamination coating and the decontamination mechanism of the detergent. At -10–10 °C, the EC/PUA/PVAc detergent has good fluidity and sprayability and forms a strippable coating. The tensile strength of the decontamination coating can be as high as 26.4 MPa, and its 180° peel strength on ceramic tile, glass, stainless steel, cement, marble are 0.49 ± 0.08 N/m, 1.82 ± 0.41 N/m, 3.03 ± 1.65 N/m, 35.60 ± 1.17 N/m, 44.43 ± 4.10 N/m, respectively. The decontamination factors ranged from 3.32 to 10.02, with a decontamination rate above 85%.

Effects of Detergents on the Spectral Features of B820 Bacteriochlorophyll a in Light-Harvesting Complex 3.

Excitonic coupling of bacteriochlorophyll (BChl) a in light-harvesting (LH) proteins of purple photosynthetic bacteria is key for efficient photon capture and energy transfer. Environmental factors can affect the spectral features of these BChl a pigments and investigating these effects can provide insight into the molecular mechanisms underlying the photosynthetic spectral tuning. The present study analyzes the spectral alterations of the Qy band of B820 BChl a within the LH3 protein in relation to the type and concentration of detergents in the buffer. Changing the detergent from lauryl dimethylamine N-oxide (LDAO) to n-dodecyl-β-d-maltoside (DDM) caused a red shift in the B820 Qy band accompanied by hyperchromism; these spectral alterations were completely reversed by exchanging back from DDM to LDAO. These results reflect the different effects of harsh vs mild detergents on the perturbation of LH3. The B820 Qy band did not change when LDAO or NaCl concentration was altered, suggesting that electrostatic effects by external components have little influence on the spectral features of B820 BChl a in LH3.