Leakage Of Substances Research Articles

A Thermostable, Modified Cathelicidin-Derived Peptide With Enhanced Membrane-Active Activity Against Salmonella enterica serovar Typhimurium.

Foodborne illness caused by consumption of food contaminated with Salmonella is one of the most common causes of diarrheal disease and affects millions of people worldwide. The rising emergence and spread of antimicrobial resistance, especially in some serotypes of Salmonella, has raised a great awareness of public health issues worldwide. To ensure safety of the food processing chain, the development of new food preservatives must be expedited. Recently, thermal- and pH-stable antimicrobial peptides have received much attention for use in food production, and represent safe alternatives to chemical preservatives. A 12-mer cathelicidin-derived, α-helical cationic peptide, P7, displayed rapid killing activity, against strains of drug-resistant foodborne Salmonella enterica serovar Typhimurium and its monophasic variant (S. enterica serovar 4,5,12:i:-) and had minimal toxicity against mouse fibroblast cells. P7 tended to form helical structure in the membrane-mimic environments as evaluated by circular dichroism (CD) spectroscopy. The action mode of P7 at the membrane-level was affirmed by the results of flow cytometry, and confocal, scanning and transmission electron microscopy. P7 killed bacteria through binding to bacterial membranes, penetration and the subsequent accumulation in S. enterica serovar Typhimurium cytoplasm. This induced membrane depolarization, permeabilization, and sequential leakage of intracellular substances and cell death. Except for sensitivity to proteolytic digestive enzymes, P7 maintained its inhibitory activity against S. enterica serovar Typhimurium in the presence of different conditions [various salts, extreme pHs and heat (even at 100°C)]. Moreover, the peptide is unlikely to induce bacterial resistance in vitro. Taken together, this study demonstrated that the membrane-permeabilizing P7 peptide has much potential as a new antimicrobial agent for use in food processing and preservation.

Use of Software on Modeling Hazardous Substance Release as a Support Tool for Crisis Management

Today’s modern society offers many new opportunities, but also many risks. Even modernization of companies cannot completely eliminate these dangers. In the smart industry, despite significant technological progress, it is necessary to work with various raw materials, including hazardous substances. It is these raw materials that will continue to pose risks in the future for industrial accidents, which cannot be ruled out. The possible release of hazardous substances can potentially have a negative impact on the environment and safety of the population. In order to deal with certain emergencies, it is necessary to allocate a large amount of funds and resources to them. The paper focuses on risk prevention in industry and the use of modern and new approaches. Specifically, it focuses on the implementation of the prevention of leakage of hazardous substances in the gaseous state from industrial facilities. The aim of the paper is to present a new approach to the prevention of leakage of hazardous substances, which provides more realistic calculations for modeling leaks and thus helps to reduce the cost of prevention. However, security in crisis management is not diminished. ALOHA CAMEO software was used for leak modeling, which the authors commonly use in practical applications and modeling in industrial enterprises in the performance of duties in the field of civil protection and crisis management. ALOHA software is used for such modeling, serving as a support tool for modeling for all crisis managers in Industry 4.0. This paper deals with the modeling of dispersion of hazardous substances with specific properties escaping from technological equipment located inside a building. This concerns the inability of the current dispersion model software to prevent the spread of the next leak inside the building containing the substance. A solution is needed to fix this problem. This issue is well illustrated by a specific example at the end of this article. The mentioned improvement of tools for simulation of industrial accidents influences the possibilities of development also in Industry 4.0. It enables more effective preparation for the management of possible accidents with regard to the appropriate spending of funds for prevention and subsequent response.

A fluorescent tool for sensing the battery-pollution event in soil samples based on Zn2+-triggering ratiometric signals

The leakage of hazardous substances from batteries leads amount of pollution events for their high toxicity and universal use all over the world. Herein, a fluorescent sensor based on triphenylamine (TPAI) was designed to monitor the battery pollution in the real soil examples. Because Zn2+composes a large part of primary and secondary batteries, TPAI was constructed for high affinity of Zn2+ within an efficient intramolecular charge transfer process that could output an obvious green-to-red (510–600 nm) signal to avoid interference from the background substances. In this way, TPAI showed a low detection limit (4.16 × 10−9 M) and high binding constants towards Zn2+ (2.82 × 1012 M−1). Moreover, TPAI exhibited excellent selectivity for Zn2+ over other metal ions and several common compounds in soil. The sensing mechanism indicated that the selectivity might need to be further optimized through adjusting the bulk of donor segment of TPAI. Then, TPAI was used to discriminate the polluted and unpolluted soil samples through a feasible on-line detection proposal under the self-made mobile platform. Combining with the fluorescent sensors and our mobile platform, we believe this work can provide a practical tool for monitoring the pollution events in diverse environmental examples.

Photo-initiated enhanced antibacterial therapy using a non-covalent functionalized graphene oxide nanoplatform.

This study describes a novel antibacterial phototherapeutic platform for highly efficient healing of bacteria-infected wounds. It is based on the photodynamic and physical actions of a zinc tetraaminophthalocyanine-modified graphene oxide nanocomposite produced via non-covalent functionalization. The nanocomposite is positively charged and can easily capture negatively charged bacteria via electrostatic interactions. The antibacterial action is two-fold: (1) reactive oxygen species are produced by the phthalocyanine photosensitizer after short-term exposure to 680 nm light and (2) the graphene oxide can physically cut bacterial cell membranes. These enhanced activities can kill Gram-positive and Gram-negative bacteria at very low dosages. An ultrastructural examination indicates that this nanocomposite causes enormous damage to bacterial morphology and leakage of intracellular substances that lead to bacterial death. A rat wound model is used to demonstrate that the proposed phototherapeutic platform has low cytotoxicity and can promote rapid healing in bacteria-infected wounds. These results suggest that the integration of different antibacterial methods into a single nanotherapeutic platform is a promising strategy for anti-infective treatment.

Study of maritime accidents with hazardous substances involved: comparison of HNS and oil behaviours in marine environment

Due to the continuous development of the chemical industry as well as the ever-increasing demand for raw materials, trend of maritime transport of chemicals and hazardous substances has significantly increased in recent decades. This growth results in a rising number of accidents involving both types of chemicals-Hazardous and Noxious Substances (HNSs) and oily substances.The continuous increasing of number of hazardous substances transported by seas, was a trigger for the competent authorities to focus on the prepare and response to a possible risk of release of such substances. Even though the risk of leakage and spill of hazardous substances is currently on the low level (as a result of the high safety standards), it still does exist.The main objective of this paper is to provide a comprehensive overview of the past accidents involving hazardous substances globally, with a focus on the HNS and oily substances spilled at the sea. The analysis is focused primarily on liquid substances, but also data on the packaged goods with the dangerous properties is involved. Another significant output is represented by recommendations about correct responding to maritime accidents involving chemicals and other dangerous substances.

Pore-forming treatments induce aggregation of Salmonella Senftenberg through protein leakage

Fresh herbs are not commonly associated with foodborne pathogens, due to the production of essential oils with antimicrobial activity. Recalls of contaminated basil, and basil outbreaks caused by Salmonella motivated studies aimed to comprehend the antimicrobial activity of basil essential oils, and to explore the mechanisms in which Salmonella can overcome them.Linalool, a major constituent of basil oil, increases the permeability of Salmonella Senftenberg cells by damaging their membrane. Linalool also induces bacterial aggregation. We hypothesized that the membrane perforation effect triggers cell aggregation through leakage of intracellular substances from live and dead cells. By exposing S. Senftenberg to additional physical (sonication) or chemical (eugenol, Triton-X-100) treatments, we showed that the aggregation is caused by various membrane-targeted treatments. Enzymatic degradation of leaked proteins restricted the bacterial aggregation, and disassembled existing aggregates. Moreover, supplemented proteins such as bacterial intracellular proteins or BSA also caused aggregation, further supporting the hypothesis that non-specific proteins trigger the bacterial aggregation.This study provides a novel understanding of the role of protein leakage in promoting bacterial aggregation. Since aggregation has significant roles in food safety and microbial ecology, this finding may establish future studies about microbial resistance via formation of clusters similar to biofilm development.

Efficiency Assessment of Resilience Engineering in Process Industries Using Data Envelopment Analysis Based on Type-2 Fuzzy Sets

Process industries have the talent of emerging high levels of turbulent behaviors and uncertainties, such as the leakage of toxic substances and explosive materials. Resilience engineering, as a novel approach, can run the effects of such actions. Resilience engineering factors involve culture, change management, knowledge acquisition, risk assessment, readiness, plasticity, reportage, the obligation of a top manager, consciousness, safety procedures, incident survey, employee participation, and competence. The present study aims to investigate resilience engineering in process industries and analyze its efficiency using the data envelopment analysis (DEA) technique. Since there are high levels of uncertainty in the factors, Type-2 fuzzy sets that have a high capability of considering uncertainty is used to analyze the efficiency. The results of this work, which is the first case in evaluating the efficiency of resilience engineering in process industries by DEA and Type-2 fuzzy sets, indicate a robust approach for analyzing the efficiency and identifying the opportunities in process industries.

Evaluation of the vital viability and their application in fungal spores’ disinfection with flow cytometry

More attention was focused on fungi contamination in drinking water. Most researches about the inactivation of fungal spores has been conducted on disinfection efficiency and the leakage of intracellular substances. However, the specific structural damage of fungal spores treated by different disinfectants is poorly studied. In this study, the viability assessment methods of esterase activities and intracellular reactive oxygen species (ROS) were optimized, and the effects of chlorine-based disinfectants on fungal spores were evaluated by flow cytometry (FCM) and plating. The optimal staining conditions for esterase activity detection were as follows: fungal spores (106 cells/mL) were stained with 10 μM carboxyfluorescein diacetate and 50 mM ethylene diamine tetraacetic acid at 33 °C for 10 min (in dark). The optimal staining conditions for intracellular ROS detection were as follows: dihydroethidium (the final concentration of 2 μg/mL) was added into fungal suspensions (106 cells/mL), and then samples were incubated at 35 °C for 20 min (in dark). The cell culturability, membrane integrity, esterase activities, and intracellular ROS were examined to reveal the structural damage of fungal spores and underlying inactivation mechanisms. Disinfectants would cause the loss of the cell viability via five main steps: altered the morphology of fungal spores; increased the intracellular ROS levels; decreased the culturability, esterase activities and membrane integrity, thus leading to the irreversible death. It is appropriate to assess the effects of disinfectants on fungal spores and investigate their inactivation mechanisms using FCM.

Emergency evacuation model assuming leakage of toxic substances in a chemical plant

Preparedness of emergency evacuation for the leakage of toxic substances in chemical plants is very important in order to reduce damage. In order to implement an emergency evacuation properly, it is necessary to comprehensively and concretely determine the conditions of the leakage and atmospheric conditions and predict the consequences of the dispersed gases. Repeated training for emergencies is also essential. In order to realize effective evacuation, a prediction model of the evacuation area that anyone can use to obtain the same results both accurately and promptly is developed in the present study. The prediction model is designed such that the wind speed and atmospheric conditions are automatically set, and the leakage rate is the only input parameter, so that anyone can use the model easily. In addition, the model can also predict the atmospheric parameters for up to 3 h and can calculate the evacuation distance so that smooth evacuation can be achieved for changing atmospheric conditions. Finally, the evacuation area is defined by statistically analysed wind fluctuations, and a series of emergency evacuation measures is implemented.

Self Healing of Cracks in Concrete with Bacteria

During the service life of concrete structures, internal and external effects and micro-cracks occur in the structure. These cracks cause leakage of harmful substances into the concrete, deterioration of the strength and durability properties of the concrete, structural damages and crashes, and the high cost of maintenance and repair of the concrete structure. It is known that water-dissolved CO2 reacts with Ca+2 ions in the concrete and can repair the concrete by forming CaCO3 (limestone) crystals with very little water solubility. However, for this type of self-repair to occur, there must be water in the environment and this repair can only be made if the cracks are too small. Recently, bacterial concrete methods which has ability to self-healing are used to overcome maintenance and repair costs. In 1994, the first study on the ability to self-healing with the extra materials that were added to the concrete during the production of concrete was published by Carolyn Dry of Illinois University. Eric Schlagen and Henk Jonkers who have been researching about self-healing concrete by adding bacterial spores and calcium lactate foods to the mixture while producing concrete have made a remarkable study in this field since 2006. Bacterial concrete, Bacillus bacterial spores in the medium of the water-activated nutrients and calcium sources in the range of appropriate pH values in the concrete due to the formation of a fibrous structure is caused by precipitation of calcite. Thus, with the precipitation of calcite, the bacteria are embedded in concrete and the concrete is provided to improve itself. In previous studies, it has been shown that the cracks and voids in the concrete are filled with the ethrengeite and C-S-H structure when the control and bio-based concrete samples examined by SEM and XRD are compared. In previous studies, it was observed that mechanical strength and durability of the concrete is increased. It should be noted that the concentration of bacteria used in the solution and the ambient pH value is specified. Although conventional maintenance and repair methods are fast reacting, and short-term efficient, bacterial concrete method is sustainable, slow and long-term efficient. In addition, it is an environmentally friendly method compared to chemical repair methods and is expected to be among the remarkable materials of the future. The high initial cost leads to a reduction in producer demand, and the development process must continue to achieve the desired results and cost. As a result, it will be possible to obtain more durable structures by not wasting time, saving money and reducing the costs of high maintenance and repair. In other respects, it is a great advantage for sustainable development. Technical studies are continuing due to the high cost and laboratory test results of the bacterial family, as well as the impacts on the survival of the bacterial family. In this study, previous studies were evaluated, and some suggestions were made based on these studies.

Quantitative risk assessment of an amine-based CO2 capture process

This study presents a risk assessment study on an amine-based CO2 capture process. Based on the critical risks identified by a hazard and operability study (HAZOP) conducted in our previous work, we performed detailed quantitative risk assessment, including frequency estimation using fault tree analysis (FTA) and consequence estimation using the process hazard analysis software tool (PHAST). As a result of our FTA study on explosion accidents in the absorber column as a top event, we identified 25 basic events and eight intermediate events that lead to the top event. The probability of a T-102 explosion was estimated to approximately 3.55E-03 per year, which satisfies international safety regulations. Additionally, we performed consequence estimation for three types of accidents in an absorber, namely toxic substance leakage, explosions, and fireballs, under two different weather conditions, namely modest and worst conditions. It was determined that in the event of a toxic substance leakage accident, the effect zone of acid gas with high toxic substance content is approximately four-times larger than that of raw gas.

Death following cocaine poisoning in body packer: Two cases report and review of the literature

Background: Body packing is the concealment of illicit drugs enclosed in containers inside the body by swallowing or insertion into the rectum or vagina, usually for transportation to escape detection by customs agents. This report seeks to explore ways of establishing general definition of body packer in the Moroccan context and assess it’s possible implications on data collection and future research. Materials and Methods: This is a descriptive and analytical retrospective study of two fatal cases related to Cocaine toxicity of body packers. The deceased underwent an autopsy at Medico-legal institute of Ibn Rochd University Hospital (UHC) of Casablanca, Morocco. Cases presentation: In these index cases, 02 male youths of foreign nationality in their twenties died in Casablanca airport. The young men took ill at the airport. Abdominal CT scan subsequently performed at the hospital revealed intra-abdominal capsules in both cases. Autopsy showed 47 whitish capsules in the stomach and colon in the first case and 67 similar capsules in the small intestine in the second case. Rapid toxicology testing in the forensic laboratory confirmed the powder to be cocaine. The cause of death was secondary to acute intoxication by leakage of cocaine substances from their packaging. Conclusion: Prevention and compliance with the legislation governing drug trafficking activities, are of vital interest in reducing the incidence of youth use as vectors of drugs and mortality consequence.

Fire Protection Regulations for Ensuring Fire Safety during Decommissioning Nuclear Power Plants in Korea

Nuclear power plants (NPPs) in Korea are required to be maintained using a defense in-depth approach to prevent leakage of radioactive substances outside the plant and allow safe shutdown in the event of a fire. Periodic testing must be conducted to ensure that the fire protection facilities perform as required by the laws for various nuclear reactor types. In June 2017, for the first time in Korea, a nuclear plant, Kori Unit 1, was permanently shut down. It was prepared for decommissioning in accordance with the fire protection regulations imposed by the regulatory body. However, a standard protocol is necessary for systematically establishing the fire protection program for decommissioning of NPPs in the future. Therefore, the nuclear legal systems of countries with many operating nuclear power plants, such as the United States, Japan, Canada, and various European countries, were reviewed and guidelines for establishing a fire protection program for decommissioning NPPs was suggested; the fire protection requirements stated by Reg Guide 1.191 (Decommissioning fire protection program for NPPs during decommissioning and permanent shutdown) were used as a model. Suggestions for establishing legal regulations to optimize fire protection programs and secure basic technology for decommissioning NPPs were also made.

Antibacterial activity and membrane-disrupting mechanism of monocaprin against Escherichia coli and its application in apple and carrot juices

In this study, the antibacterial activity of monocaprin against Gram-negative foodborne pathogens and its underlying mechanism against E. coli were investigated. It was found that monocaprin exerted excellent antibacterial effects on E. coli, Vibrio parahaemolyticus and Shigella dysenteriae with the minimum inhibitory concentration/minimum bactericidal concentration values of 1.25 mM, 0.625 mM and 0.625 mM, respectively. The results of growth curve and time-kill assay showed that monocaprin could not only delay the growth of E. coli, but quickly inactivate the cells within 15 min. The effects of monocaprin on membrane integrity, inner and outer membrane permeability, proton motive force, and its interaction with model membranes and cell morphology were investigated to explore the antibacterial mechanism of monocaprin. The results indicated that monocaprin rapidly inactivated E. coli by penetrating its outer membrane, then destroying the phospholipid bilayer structure of the inner membrane, as well as dissipating the proton motive force, resulting in increases of the permeability of the outer and inner membranes and leakage of intracellular substances. Besides, monocaprin significantly reduced the viability of E. coli in apple and carrot juices at 4 °C and 25 °C without changing their sensory properties.

Ecological monitoring system of the atmosphere

The research is targeted at the development and testing of a hardware-software system for environmental monitoring of atmospheric air in real time. The relevance of creating the system is substantiated in the article where it is shown that one cannot obtain operational data on the degree of atmospheric air pollution using available means, although this information is important for the population of large cities and industrial centers. The results of the creation and use of the automated system for monitoring atmospheric air using the modeling of transfer of pollutants are presented. The system was based on a hardwaresoftware complex consisting of a microcomputer, pollution sensors, a wireless communication module, and an unmanned aerial vehicle. Real-time pollution indicators are processed in order to build up-to-date maps, including to provide the opportunity to choose the optimal route taking into account the adverse effects of pollution. The developed mobile application provides the opportunity for the end user to receive information on-line and make forecasts based on the data on wind strength and direction in the short and medium term. The OND-86 methodology, which is mandatory in the Republic of Belarus, was chosen as the main model for the transfer of pollutants in the air. Information about the strength and direction of the wind for building forecasts is taken from open Internet sources of weather data. Using real data on the mass of emissions, a map of the planned concentration is constructed, which is scattered in proportion to the distance from the source of the emission, taking into account the strength and direction of the wind. The forecast obtained in this way can be used to select the optimal route, optimize traffic flows and organize actions in emergency situations associated with leakage and emissions of harmful substances.

Developing of Low-Cost Air Pollution Sensor-Measurements with the Unmanned Aerial Vehicles in Poland.

This article presents the capabilities and selected measurement results from the newly developed low-cost air pollution measurement system mounted on an unmanned aerial vehicle (UAV). The system is designed and manufactured by the authors and is intended to facilitate, accelerate, and ensure the safety of operators when measuring air pollutants. It allows the creation of three-dimensional models and measurement visualizations, thanks to which it is possible to observe the location of leakage of substances and the direction of air pollution spread by various types of substances. Based on these models, it is possible to create area audits and strategies for the elimination of pollution sources. Thanks to the usage of a multi-socket microprocessor system, the combination of nine different air quality sensors can be installed in a very small device. The possibility of simultaneously measuring several different substances has been achieved at a very low cost for building the sensor unit: 70 EUR. The very small size of this device makes it easy and safe to mount it on a small drone (UAV). Because of this device, many harmful chemical compounds such as ammonia, hexane, benzene, carbon monoxide, and carbon dioxide, as well as flammable substances such as hydrogen and methane, can be detected. Additionally, a very important function is the ability to perform measurements of PM2.5 and PM10 suspended particulates. Thanks to the use of UAV, the measurement is carried out remotely by the operator, which allows us to avoid the direct exposure of humans to harmful factors. A big advantage is the quick measurement of large spaces, at different heights above the ground, in different weather conditions. Because of the three-dimensional positioning from GPS receiver, users can plot points and use colors reflecting a concentration of measured features to better visualize the air pollution. A human-friendly data output can be used to determine the mostly hazardous regions of the sampled area.

Autonomous Search of Radioactive Sources through Mobile Robots.

The research of robotic autonomous radioactivity detection or radioactive source search plays an important role in the monitoring and disposal of nuclear safety and biological safety. In this paper, a method for autonomously searching for radioactive sources through mobile robots was proposed. In the method, by using a partially observable Markov decision process (POMDP), the search of autonomous unknown radioactive sources was realized according to a series of radiation information measured by mobile robot. First, the factors affecting the accuracy of radiation measurement during the robot’s movement were analyzed. Based on these factors, the behavior set of POMDP was designed. Secondly, the parameters of the radioactive source were estimated in the Bayesian framework. In addition, through the reward strategy, autonomous navigation of the robot to the position of the radiation source was achieved. The search algorithm was simulated and tested, and the TurtleBot robot platform was used to conduct a real search experiment on the radio source Cs-137 with an activity of 37 MBq indoors. The experimental results showed the effectiveness of the method. Additionally, from the experiments, it could been seen that the robot was affected by the linear velocity, angular velocity, positioning accuracy and the number of measurements in the process of autonomous search for the radioactive source. The proposed mobile robot autonomous search method can be applied to the search for lost radioactive sources, as well as for the leakage of substances (nuclear or chemical) in nuclear power plants and chemical plants.

A study on the evaluation of odor substance leakage from odor source of public environment facilities

A study on the evaluation of odor substance leakage from odor source of public environment facilities

Revealing the active period and type of tetracycline stress on Chinese cabbage (Brassica rapa L.) during seed germination and post-germination.

Stresses of antibiotics can cause strains (i.e. effects) on seed at germination and post-germination stages. But there is a lack of research on the period and type of the effects at present. In this study, Chinese cabbage (Brassica rapa L.), a commonly used crop, was selected to investigate the effect of tetracycline (TC), a major-use antibiotic, on its seed during different periods of the stages. Results showed that there were no significant differences among the germination energy (GE) of control (CK) and treatments, but radicle length (RL) of the treatments, the exposure to TC at post-germination stage (i.e. radicle elongation stage), was all significantly less than that of CK. The initial stage of radicle elongation was the earliest and most sensitive period at which the stress of TC caused the plastic effect on seed. Moreover, the action of TC stress on seed did not have a delayed characteristic. The result of RL was identical to the leakage of intracellular substances at radicle fast elongation stage, but not the Evan's blue trapped by radicle. We concluded that TC inhibited the elongation of radicle through weakening the cellular metabolic activity rather than leading to the loss of cellular membrane integrity. It should be paid more attention to the phytotoxicity of TC in the field due to its active characteristics revealed in our study.

Effect of curcumin on the quality properties of millet fresh noodle and its inhibitory mechanism against the isolated spoilage bacteria.

Fresh noodle product has attracted increasing attention due to its nutritive value and convenience. However, the relative short shelf life of fresh noodle is still a concern that needs to resolve. The objective of this study was to evaluate the preservative effect of curcumin (CUR) on millet fresh noodle during storage and its inhibitory mechanism against two isolated spoilage bacteria (Bacillus cereus and Escherichia coli). The effects of CUR were evaluated with regard to the quality and sensory evaluation of millet fresh noodle, the changes of bacterial growth curve, cell intracellular substances, cell viability, and bacterial morphology. The results showed that CUR could decrease the total colony number and prolong the shelf life of millet fresh noodle stored at 25°C from 20 to 30 hr. Quality and sensory evaluations showed that addition of CUR caused no negative effect on noodle quality and was determined to be sensory acceptable. The minimum inhibitory concentration of CUR against B. cereus and E. coli was 0.125 and 0.5 mg/ml, respectively. The growth curve revealed that CUR presented good antibacterial effect against both bacteria. The leakage of intracellular substances, cell viability, and bacterial morphology change after CUR treatment confirmed the destructive effects of CUR on plasma membrane integrity. These results indicated that CUR had the potential to be applied as a natural preservative for controlling the growth of spoilage microorganisms and extending the shelf life of millet fresh noodle.