Persistence of the Antibacterial and Antiviral Effects after Skin Cleansing ~A New Approach to Suppress the Contact Infection~.

Handwashing represents an important personal hygiene measure for preventing infection. Herein, we report the persistence of antibacterial and antiviral effects after handwashing with fatty acid salt-based hand soap. To this end, we developed a new in vitro test method to measure persistence, utilizing coacervation formed by anionic surfactants and cationic polymers to retain highly effective soap components against each bacterium and virus on the skin.

Probability Density Functional Method of Enzyme Effect on Denatured Protein Soil.

Protein soils must be removed for both appearance and hygienic reasons. They are denatured by heat treatment or bleaching and cleaned using enzymes. Among the various types of protein soils, blood soils are the most noticeable and known to be denatured by heat and bleaching by oxidation.

Improving the Removability of Mud Stains by Combining a Homopolymer and a Chelating Agent.

To improve the detergency of mud stains without triphosphate, we developed a new composition that enhances the detergency of mud stains more efficiently. To develop the composition, a new correction method based on the probability density functional method was used to compare the results of approximately 100 cleaning tests conducted on different days using various active ingredients. As a result of various evaluations, it was found that the combination of a homopolymer with a molecular weight of approximately 2000 and a chelating agent can effectively improve the detergency of particle stains.

Analysis of Cleaning Power Using New Cleaning Kinetics and Interfacial Science Studies on Aquatic Toxicity of Surfactants.

Studies devised through the fusion of cleaning and environmental sciences can be summarized as follows: new cleaning kinetics applying a probability density function and a surface chemical approach to the aquatic toxicity of surfactants. Cleaning power analysis using the probability density functional method combines conventional cleaning kinetics using a first-order reaction equation with a risk analysis method using a probability density function. It is possible to analyze the cleaning mechanism from the obtained parameter values.

Effect of Water Hardness on Acute Aquatic Toxicity of Fatty Acid Salts.

The acute aquatic toxicity of anionic surfactants, including fatty acid salts, changes depending on water hardness. Generally, the acute aquatic toxicity of Daphnia magna is caused by the adsorption of surfactants and other substances. Despite the low environmental risk, the effect of water hardness on the acute aquatic toxicity of soap should be discussed to improve the assessment accuracy.

Ultrasonic Cleaning for Irrigating Purulent Substances during Laparoscopic Gastrointestinal Surgery.

To improve the outcome of laparoscopic gastrointestinal surgery, improvement in the technology for removing purulent substances from the abdominal cavity is required. Ultrasonic cleaning technology may be suitable for the task. However, it is necessary to examine cleaning efficiency and safety through model tests that can lead to clinical trials for practical use.

A Small-scale Washing Test That Reproduces the Mechanical Forces Occurring Inside a Commercial Washing Machine.

A small-scale washing test model was proposed to reproduce the mechanical forces occurring inside a household washing machine in Japan. Washing tests were conducted using household washing machines, a tergotometer, and four types of small-scale washing test models using JIS-designated artificially soiled fabric. As a result of conducting washing tests in 10 households during winter and summer, we determined that the mechanical force of the washing machine was equivalent to 90-100 rpm agitation by a tergotometer.

Classification of the Biodegradation Factors of Linear Alkylbenzene Sulfonate.

The conditions that significantly affect the biodegradability of linear alkylbenzene sulfonate (LAS) based on previous studies were categorized. Among these previous studies, we focused on those that used activated sludge and river water as inocula in biodegradation studies. Analyzing the results of these studies revealed two types of methylene blue active substances (MBAS) removal curves in primary biodegradation, and the study conditions that differentiated the two types were analyzed, along with verification studies.

Combined Use of Reducing Agents and Biodegradable Chelating Agent for Iron Rust Removal.

Since many of the current chemicals used to remove iron rust are hazardous to the environment and human health, the combined use of a reducing agent and a biodegradable chelating agent has been suggested as an environmental friendly and highly safe alternative. In the present work, the compatibility of the newly devised cleaning test with a model iron rust stain was confirmed by X-ray diffraction and scanning electron microscopy. Additionally, the cleaning efficiency of the method was evaluated by X-ray fluorescence.

Synergistic Action of Temperature and pH Factors in the Cleaning of Fatty Acids Soils; Analyzed by Probability Density Functional Method.

In this study, the interaction between the temperature and the pH of soil containing fatty acids with sodium dodecyl sulfate (SDS) aqueous solution was investigated to elucidate their synergistic effect in cleaning. A tergotometer was used for the cleaning test, and the cleaning results were analyzed by the probability density functional method, using the calculated parameter, µ , as an index of the cleaning power. The increase in µ by one of the factors was defined as ΔX or ΔY and the increase in µ by the both factors was defined as Δ(X + Y).

Kinetic analysis of hemoglobin detergency by probability density functional method.

In this study, washing tests were performed using samples prepared by contaminating fabrics with hemoglobin, and a kinetic analysis was conducted based the probability density functional method, which expresses the cleaning power using two parameters σrl (related to the cleaning mechanism) and μrl (related to the level of cleaning power). This method allows for the processing of uncertainties specific to protein washing under the assumption that the soil adhesion and detergency are in accordance with a normal distribution. A certain amount of hemoglobin solution was soaked in a cloth, dried, and steam-treated, and then used as a sample for a cleaning test.

Effect of Awareness and Habits of Oral Care on Life Satisfaction.

Purpose: New methods of public education in oral care must be developed, because the public understanding of the importance of oral care is insufficient. This questionnaire study examined the parameters 'awareness and attitude relevant to teeth and mouth' and 'consciousness and attitude of daily life' in order to clarify what kind of information is needed for public education in oral care.

Materials And Methods: Data gathered in a survey of oral care behaviours and lifestyle among the elderly were analysed for oral care awareness and health of the teeth using the factor analysis method.

Analysis of Cleaning Process for Several Kinds of Soil by Probability Density Functional Method.

A method of analyzing the detergency of various soils by assuming normal distributions for the soil adhesion and soil removal forces was developed by considering the relationship between the soil type and the distribution profile of the soil removal force. The effect of the agitation speed on the soil removal was also analyzed by this method. Washing test samples were prepared by soiling fabrics with individual soils such as particulate soils, oily dyes, and water-soluble dyes.

Derivation of quantitative removal efficiency of protein stain from K/S value of washing test fabric soiled with hemoglobin.

We have improved a previous method for the preparation of hemoglobin-soiled fabrics in order to facilitate quantitative calculation of the efficiency with which protein stains can be removed from such materials. We then evaluated the sensitivity of surface reflectance as a method for stain quantification. Test fabrics were made by spotting a white fabric with a certain amount of hemoglobin solution and drying it.

Quantitative determination of colored oily soil adhering to metal surface using digital image data.

A method for calculating the amount of colored soil on a flat metal surface from digital image data was examined. Round samples cut out of SUS tape were soiled with oily soil mixed with sudan III, placed in sample bottles, and washed using a tube rotator. Images of the samples before and after the washing process were captured using a CCD camera and the image data were processed by a computer.

Effects of surface activity on aquatic toxicity of binary surfactant mixtures.

The purpose of this study was to discuss the effects of surface activity on the aquatic toxicity of binary surfactant mixtures comprising anionic, nonionic, and cationic surfactants. Surface tension was measured to determine the cmc (critical micelle concentration), and acute aquatic toxicity tests were conducted on Daphnia magna to obtain 24h-EC(50) (24h 50% effective concentration). TU (toxic unit) was calculated to evaluate the toxicity of the mixture.

Decreases in surface activities and aquatic toxicities of linear alkylbenzene sulfonate and alcohol ethoxylates during biodegradation.

We discussed the relation between aquatic toxicity and interfacial activity during biodegradation with using LAS (Linear Alkylbenzene Sulphonate) and AE (Alcohol Ethoxylate). The change of death rate of Daphnia magna, surface tension, concentration of surfactant, and biodegradation by oxygen demand during biodegradation were measured. As a result, a rapid decrease in toxicity and rapid increase in surface tension were observed within the time before biodegradation based on oxygen demand started to increase.

Application of statistical analysis to mixed soil detergency.

In previous studies, statistical method using distribution of detergent power and that of resistance of soil against washing was applied to analyze detergency of oily soil and solid particle soil. In this paper, this method was applied to an analysis of detergency of mixed soil. Artificially soiled cloth prepared by aqueous dispersion method was used as a mixed soil sample.

Large decrease in acute aquatic toxicity of linear alkylbenzene sulfonate in hard water and seawater by adding adsorbent.

LAS (Linear Alkylbenzene Sulphonate) shows relatively high aquatic toxicity in hard freshwater or seawater. In this paper, we studied the effect of adsorbent on the aquatic toxicity of LAS in hard freshwater and seawater. Daphnia magna and Artemia salina were used for acute aquatic toxicity test in freshwater and seawater, respectively.

Effects of water hardness and existence of adsorbent on toxic surface tension of surfactants for aquatic species.

We have studied the effectiveness of surface tension on surfactants risk assessment. gamma(tox) was defined as surface tension at a point where acute aquatic toxicity of a surfactant emerges. Oryzias latipes, Daphnia magna, and Podocopida were used for acute aquatic toxicity test of 7 surfactants and 3 detergents.

Statistical analysis of washing efficiency for solid particle soil.

In a previous study, statistical method using two distributions was applied to analyze detergency of oily soil. The method uses statistical distributions of detergent power and adhesive force of soil. In this paper, this method was applied to an analysis of detergency of solid particles.