During the recent emergence of COVID-19, an increased practice of hand hygiene coincided with the reduced incidence of the norovirus epidemic in Japan, which is similar to experience with the pandemic flu in 2009. We investigated the relationship between the sales of hand hygiene products, including liquid hand soap and alcohol-based hand sanitizer, and the trend of norovirus epidemic. We used national gastroenteritis surveillance data across Japan in 2020 and 2021 and compared the base statistics of incidence of these two years with the average of the previous 10 years (2010-2019). We calculated the correlations (Spearman's Rho) between monthly sales of hand hygiene products and monthly norovirus cases and fitted them to a regression model. In 2020, there was no epidemic, and the incidence peak was the lowest in recent norovirus epidemics. In 2021, the incidence peak was delayed for five weeks to the usual epidemic seasons. Correlation coefficients between monthly sales of liquid hand soap and skin antiseptics and norovirus incidence showed a significantly negative correlation (Spearman's Rho = -0.88 and p = 0.002 for liquid hand soap; Spearman's Rho = -0.81 and p = 0.007 for skin antiseptics). Exponential regression models were fitted between the sales of each hand hygiene product and norovirus cases, respectively. The results suggest hand hygiene using these products is a potentially useful prevention method against norovirus epidemics. Effective ways of hand hygiene for increasing the prevention of norovirus should therefore be studied.
Humans ; Japan/epidemiology* ; COVID-19 ; Hand Hygiene ; Soaps ; Anti-Infective Agents, Local ; Norovirus

The effective components of flavonoids in the "Pueraria lobata-Hovenia dulcis" drug pair have low bioavailability in vivo due to their unstable characteristics. This study used microemulsions with amphoteric carrier properties to solve this problem. The study drew pseudo-ternary phase diagrams through titration compatibility experiments of the oil phase with emulsifiers and co-emulsifiers and screened the prescription composition of blank microemulsions. The study used average particle size and PDI as evaluation indicators, and the central composite design-response surface method(CCD-RSM) was used to optimize the prescription; high-dosage drug-loaded microemulsions were obtained, and their physicochemical properties, appearance, and stability were evaluated. The results showed that when ethyl butyrate was used as the oil phase, polysorbate 80(tween 80) as the surfactant, and anhydrous ethanol as the cosurfactant, the maximum microemulsion area was obtained. When the difference in results was small, K_(m )of 1∶4 was chosen to ensure the safety of the prescription. The prescription composition optimized by the CCD-RSM was ethyl butyrate(16.28%), tween 80(9.59%), and anhydrous ethanol(38.34%). When the dosage reached 3% of the system mass, the total flavonoid microemulsion prepared had a clear and transparent appearance, with average particle size, PDI, and potential of(74.25±1.58)nm, 0.277±0.043, and(-0.08±0.07) mV, respectively. The microemulsion was spherical and evenly distributed under transmission electron microscopy. The centrifugal stability and temperature stability were good, and there was no layering or demulsification phenomenon, which significantly improved the in vitro dissolution of total flavonoids.
Polysorbates/chemistry* ; Flavonoids ; Pueraria ; Surface-Active Agents/chemistry* ; Ethanol ; Emulsions ; Particle Size ; Solubility

With the continuous exploration of microemulsions as solvents for traditional Chinese medicine extraction, polyoxyethy-lene(35) castor oil(CrEL), a commonly used surfactant, is being utilized by researchers. However, the problem of detecting residues of this surfactant in microemulsion extracts has greatly hampered the further development of microemulsion solvents. Based on the chemical structures of the components in CrEL and the content determination method of castor oil in the 2020 edition of the Chinese Pharmacopoeia(Vol. Ⅳ), this study employed gas chromatography(GC) and single-factor experiments to optimize the preparation method of methyl ricinoleate from CrEL. The conversion coefficient between the two was validated, and the optimal sample preparation method was used to process microemulsion extracts of Zexie Decoction from three batches. The content of methyl ricinoleate generated was determined, and the content of CrEL in the microemulsion extracts of Zexie Decoction was calculated using the above conversion coefficient. The results showed that the optimal preparation method for CrEL was determined. Specifically, 10 mL of 1 mol·L~(-1) KOH-methanol solution was heated at 60 ℃ for 15 min in a water bath. Subsequently, 10 mL of boron trifluoride etherate-methanol(1∶3) solution was heated at 60 ℃ for 15 min in a water bath, followed by extraction with n-hexane twice. CrEL could stably produce 20.84% methyl ricinoleate. According to this conversion coefficient, the average mass concentration of CrEL in the three batches of Zexie Decoction microemulsion extracts was 11.94 mg·mL~(-1), which was not significantly different from the CrEL mass concentration of 11.57 mg·mL~(-1) during microemulsion formulation, indicating that the established content determination method of this study was highly accurate, sensitive, and repeatable. It can be used for subsequent research on microemulsion extracts of Zexie Decoction and provide a reference for quality control of other drug formulations containing CrEL.
Polyethylene Glycols/chemistry* ; Castor Oil ; Methanol ; Surface-Active Agents/chemistry* ; Solvents ; Water/chemistry* ; Emulsions/chemistry*

Aims: This study was aimed to investigate the anti-inflammatory and anti-rheumatoid effects of the Bacillus amyloliquefaciens derived surfactin. Methodology and results: Crude and biosurfactant extracts were analyzed using thin-layer chromatography to determine the presence of biosurfactant. Both extracts were evaluated for their inhibitory effects against the acetylcholinesterase and 5-lipoxygenase enzymes. Human synovial cells were induced with TNF-α and IL-1β. The percentages of the cell viability for both normal and induced cells were determined with an MTT assay. Results showed that surfactin was detected in the biosurfactant extract and demonstrated higher inhibitory effects compared to the crude extract against both inhibitory enzymes acetylcholinesterse (IC50=30.60 μg/mL) and lipoxygenase (IC50=110.10 μg/mL). Both crudes showed no cytotoxic effects at the highest concentration used (50 μg/mL) against normal human synovial cells but showed active reactions against the induced cells. The anti-proliferative effects of biosurfactant and crude extracts were in dose-dependent manner. Conclusion, significance and impact of study Notably, surfactin obtained from B. amyloliquefaciens has shown an inhibitory effect against pro-inflammatory enzymes and cell viability of the induced rheumatoid arthritis cell line. These results highlighted the therapeutic potential of surfactin application as an anti-inflammatory agent for arthritis treatment. Further study is needed to elucidate the mechanisms underlying the anti-inflammatory effect of surfactin.
Bacillus amyloliquefaciens ; Surface-Active Agents ; Anti-Inflammatory Agents ; Rheumatoid Factor

Aims: This study was aimed to isolate and characterize biosurfactant producing bacteria from Mile 2 and Ologe Lagoon which are sinks for domestic and industrial waste waters and potential source of value added bioresources such as biosurfactants, hydrocarbon degraders and organisms with potential for biotechnological applications. Methodology and results: Physicochemical parameters of the two lagoon waters were analyzed using standard procedures. Bacteria were isolated using enrichment techniques on 1% Escravos light crude oil, palm oil and groundnut oil on mineral salt medium (MSM). Biosurfactant production by the isolates was assayed by hemolytic activity, oil spread test, blue agar test and emulsification activity. Isolates were identified using their colony morphologies and biochemical characteristics, while the antibiotic susceptibility of the isolates was determined using multidisc. The physicochemistry of the lagoon water showed high nitrate content of 15.7 mg/L and 19.6 mg/L for Mile 2 and Ologe Lagoon, respectively. Total hydrocarbon content (THC) of both lagoon waters was low, with values 0.53 mg/L for Mile 2 Lagoon and 0.44 mg/L for Ologe Lagoon. The predominant genera of bacteria identified include Micrococcus, Bacillus, Pseudomonas, Acinetobacter, Stomatococcus and Moraxella. A total of 23 bacterial isolates were tested for hemolytic activity, of which 13 showed β-hemolysis which is presumptive for biosurfactant production, 5 showed α-hemolysis and the remaining 5 exhibited γ-hemolysis. Majority of the isolates were positive for oil spread assay and blue agar test (19) indicating production of anionic biosurfactant. The isolates showed good emulsification activity; AGG3 (67.7%), AGG1 (62.3%), AGG2 (60%), AGG4 (60%), MTP2 (56%), AGC4 (54%) and the least emulsification value of 23.3% for strain AGP1. Most of the isolates were susceptible to ciprofloxacin, perfloxacin and showed resistance to septrin and erythromycin. Conclusion, significance and impact of study This study showed that Mile 2 and Ologe Lagoon are a potential source of biosurfactant producers with diverse emulsification properties and prospective industrial applications. This would have implication for economic empowerment, as well as sustainable and environmentally friendly clean-up technology in both locally and globally.
Surface-Active Agents ; Nigeria

Aims: This study aims to produce Achromobacter biosurfactant in nutrient-rich and nutrient-limited media. Methodology and results: This study conducted fermentation on nutrient-rich and nutrient-limited media using a minimal salt medium (MSM). Dextrose and sodium citrate were used as sole carbon supplemented with 0.5% yeast extract for nutrient-rich media, while nutrient-limited media used molasses and rice straw hydrolysate (RSH) at variations of concentrations of 100 ppm and 200 ppm. The research was performed over 120 h and evaluated from growth response, surface tension and emulsification activity. The study revealed that the best surface tension value was when 2% (w/v) sodium citrate was used as C-source and 0.5% (w/v) yeast extract as N-source, after 72 h upon incubation at 30 °C/120 rpm having 45.45 ± 2.19 mN/m with emulsification activity 24.54 ± 3.42%. Whereas the best result of the nutrient-limited medium was obtained by RSH at a concentration of 200 ppm having 48.86 ± 5.36 mN/m. Conclusion, significance and impact of study The experiment showed that nutrient-limited medium from rice straw hydrolysate could compete with the nutrient-rich medium. The use of rice straw will contribute to the reduction of biosurfactant production costs and valorisation of agricultural waste.
Achromobacter denitrificans ; Surface-Active Agents

This study explores the emulsifying material basis of Angelicae Sinensis Radix volatile oil (ASRVO) based on partial least squares (PLS) method and hydrophile-lipophile balance (HLB) value.The turbidity of ASRVO emulsion samples from Gansu,Yunnan,and Qinghai was determined and the chemical components in the emulsion were analyzed by GC-MS.The PLS model was established with the chemical components as the independent variable and the turbidity as the dependent variable and evaluated with indexes R~2X and R~2Y.The chemical components which were in positive correlation with the turbidity were selected and the HLB values were calculated to determine the emulsification material basis of ASRVO.The PLS models for the 81 emulsion samples had high R~2X and R~2Y values,which showed good fitting ability.Seven chemical components,2-methoxy-4-vinylphenol,trans-ligustilide,3-butylidene-1(3H)-isobenzofuranone,dodecane,1-methyl-4-(1-methylethylidene)-cyclohexene,trans-beta-ocimene,and decane,had positive correlation with turbidity.Particularly,the HLB value of 2-methoxy-4-vinylphenol was 4.4,which was the HLB range of surfactants to be emulsifiers and 2-methoxy-4-vinylphenol was positively correlated with turbidity of the ASRVO emulsion samples from the main producing area.Therefore,2-methoxy-4-vinylphenol was the emulsifying material basis of ASRVO.The selected emulsifying substances can lay a foundation for exploring the emulsification mechanism and demulsification solution of ASRVO.
China ; Emulsions ; Least-Squares Analysis ; Oils, Volatile ; Surface-Active Agents

To effectively solve the serious impact of high oil in the kitchen wastewater on the downstream treatment process, an excellent oil-degrading strain Aeromonas allosaccarophila CY-01 was immobilized to prepare Chitosan-Aeromonas pellets (CH-CY01) by using chitosan as a carrier. Oil degradation condition and efficiency of CH-CY01 pellets were assessed. The growth of immobilized CH-CY01 was almost unaffected, and the maximum degradation rate of soybean oil was 89.7%. Especially at 0.5% NaCl concentration, oil degradation efficiency of CH-CY01 was increased by 20% compared with free cells. In the presence of a surfactant (sodium dodecylbenzene sulfonate) at 1 mg/L, the degradation efficiency of oil by CH-CY01 was increased by 40%. Moreover, using the high-oil catering wastewater as the substrate, more than 80% of the solid oil was degraded with 1% (V/V) CH-CY01 pellets treatment for 7 days, significantly higher than that of free cells. In summary, immobilized CH-CY01 significantly improved the efficiency of oil degradation.
Aeromonas ; Chitosan ; Surface-Active Agents ; Waste Water

Aims: Rhamnolipids are seeking utmost attention as a new class of biosurfactants having promising potential in diverse fields as they offer a wide range of advantages over chemically synthesised surfactants. However, the high extraction costs make large scale production face difficulty. In present study, hydrocarbon degrading bacteria Pseudomonas aeruginosa UKMP14T was exploited for its biosurfactant producing ability including a comparative study between different extraction procedures for its recovery. In addition to this, the recovered biosurfactant was explored for its potential application as an antimicrobial agent. Methodology and results: The production of rhamnolipid biosurfactant was confirmed through various detection methods which are drop-collapse test, oil spreading assay, emulsification index, cetyltrimethylammonium bromide (CTAB) assay and hemolytic assay. The test strain P. aeruginosa UKMP14T showed positive results for all the detection assays. Following this, shake flask cultivation was carried out for several time intervals (1, 3, 5, 7 and 9 days) to discover the optimum time for rhamnolipid biosurfactant production. The results were evaluated by quantifying the rhamnolipid yield using Anthrone method and maximum yield was obtained on day 7. Then, three commonly employed rhamnolipid biosurfactant extraction methods (acid precipitation, solvent extraction and zinc sulphate precipitation) were incorporated for the extraction of rhamnolipid biosurfactant. Among these methods, organic solvent extraction (using methanol, chloroform and acetone in 1:1:1 ratio) gave the highest yield (7.37 ± 0.81 g/L) of biosurfactant, followed by zinc sulphate precipitation (5.83 ± 0.02 g/L), whereas acid precipitation gave the lowest yield (2.8 ± 0.12 g/L) and required longer time (30 days). Finally, the antimicrobial activity of several concentrations of rhamnolipid was tested using modified microdilution method and highest antibacterial activity (in the form of percent reduction in growth) of 95.05% and 91.89% was recorded for Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 11632, respectively, at 100 µg/mL concentration of rhamnolipid biosurfactant. Conclusion, significance and impact of study The ability of P. aeruginosa UKMP14T in producing rhamnolipid biosurfactant was confirmed. Despite the higher yield obtained by organic solvent extraction method, the recovery technique (involving the separation of solvent system) caused some loss in product. In addition, the transfer and storage of rhamnolipid was challenging using solvent extraction in comparison to acid precipitation and zinc sulphate precipitation. On the other hand, recovery using acid precipitation suffered from lowest yield of rhamnolipid. Therefore, zinc sulphate precipitation is prioritised over the other two methods. Furthermore, the antimicrobial potential of rhamnolipid biosurfactant was tested successfully for as low as 10 µg/mL concentration against E. coli ATCC 10536 and S. aureus ATCC 11632. Therefore, the recovery cost of a high value product like rhamnolipid can be reduced by incorporating the results of this study in the downstream processing and promote rhamnolipid biosurfactant as a potential antimicrobial agent.
Glycolipids--biosynthesis ; Surface-Active Agents ; Pseudomonas aeruginosa

To prepare and optimize the self-microemulsion co-loaded with tenuifolin and β-asarone(TF/ASA-SMEDDS) and evaluate its quality. The prescription compositions of TF/ASA-SMEDDS were screened by solubility test, single factor test and pseudo-tern-ary phase diagram, and the prescriptions were further optimized by Box-Behnken response surface method, with the drug loading and particle size as the evaluation indexes. Then the optimized TF/ASA-SMEDDS was evaluated for emulsified appearance, particle size, morphology and drug release in vitro. The optimized prescription for TF/ASA-SMEDDS was as follows: caprylic citrate triglyceride polyoxyethylene castor oil-glycerol(10.8∶39.2∶50), drug loading of(5.563±0.065) mg·g~(-1) for tenuifolin and(5.526±0.022) mg·g~(-1) for β-asarone; uniform and transparent pan-blue nanoemulsion can be formed after emulsification, with particle size of(28.84±0.44) nm. TEM showed that TF/ASA-SMEDDS can form spherical droplets with a uniform particle size after emulsification; In vitro release test results showed that the drug release rate and cumulative release of tenuifolin and β-asarone were significantly improved. The preparation process of TF/ASA-SMEDDS was simple and can effectively improve in vitro release of tenuifolin and β-asarone.
Anisoles ; Biological Availability ; Diterpenes, Kaurane ; Drug Delivery Systems ; Emulsions ; Particle Size ; Solubility ; Surface-Active Agents