Correlation between disinfection efficacy and cumulative amount of free chlorine reaching various positions during ultrasonic fogging with hypochlorite solution.

When a hypochlorite solution is ultrasonically fogged in a room, free chlorine, i.e., HOCl and OCl-, reaches various positions in two forms: fine fog droplets and gaseous hypochlorous acid（HOCl(g)）. In this study, the cumulative amount of free chlorine reaching various positions on the floor away from the fogger was measured in a 90-m3 room, using a sulfamate-carrying glass-fiber filter indicator. The fine droplets were blown out from the fogger into the spaces at different discharge port angles of 30 - 90°. Free chlorine was successfully trapped by sulfamate, forming monochlorosulfamate, which was stably retained on the indicator. The cumulative amount of free chlorine（ ng/indicator） increased with fogging time at each position and depended on the blow angle and distance from the fogger. Minor differences in the HOCl(g) concentration near the floor at all positions were observed. The disinfection efficacy of the fogging treatment against Staphylococcus aureus on wet surfaces was relatively higher at positions near the fogger and lower at positions far from the fogger. At each discharge port angle, a strong correlation between the logarithmic reduction in relative viable cells and the cumulative amount of free chlorine reaching S. aureus plates was observed. The slopes of the regression lines of correlation diagrams as a function of the cumulative amount of free chlorine were between -0.0362 and -0.0413 ng-1. This study demonstrated that the cumulative amount of free chlorine measured using the filter indicator could reflect the sum of the free chlorine of both fine droplets and HOCl(g), and that the disinfection efficiency depended on the cumulative amount of free chlorine reaching different areas.

Impact of fresh-frozen plasma from male-only donors versus mixed-sex donors on postoperative respiratory function in surgical patients: a prospective case-controlled study.

BACKGROUND: To reduce the risk of transfusion-related acute lung injury (TRALI), plasma products are mainly made from male donors in some countries because of the lower possibility of alloimmunization; other countries are considering this policy. The advantage of male-only fresh-frozen plasma (FFP) should be examined in a prospective case-control study. STUDY DESIGN AND METHODS: This study compared pulmonary function after the transfusion of FFP derived from either male donors only (FFP-male) or mixed donors (FFP-mixed) in informed surgical patients treated at a tertiary university hospital in Japan. The factors contributing to pulmonary distress (PD) after transfusion were then statistically examined. RESULTS: Eighty-two patients participated in this study (FFP-male, n = 55; FFP-mixed, n = 27). Nineteen patients developed PD (PaO(2)/FiO(2) ratio [P/F] < 300) within 6 hours after transfusion: seven had congestive pulmonary edema (transfusion-associated circulatory overload), five had permeability pulmonary edema (possible TRALI), and seven had no apparent pulmonary edema. A multivariate logistic regression analysis revealed that the use of cardiopulmonary bypass and preoperative liver dysfunction were significantly associated with a P/F of less than 300 (odds ratios [ORs], 8.95 [p = 0.004] and 6.54 [p = 0.005], respectively), while the use of FFP-male was significantly associated with the absence of PD (OR, 0.219; p = 0.022). All the patients with possible TRALI had received either white blood cell or granulocyte antibody-positive FFP. The lysophosphatidylcholine level was not correlated with PD. CONCLUSIONS: Our data suggests that the use of FFP derived from male donors may be advantageous for posttransfusion pulmonary function, although PD is also determined by background characteristics.

Thickening properties and emulsification mechanisms of new derivatives of polysaccharide in aqueous solution 2. The effect of the substitution ratio of hydrophobic/hydrophilic moieties.

The thickening properties and association behavior of aqueous solutions of HHM-HEC (hydrophobically-hydrophilically modified hydroxyethyl cellulose) with various hydrophobic and hydrophilic substitution degrees were investigated. The HHM-HEC was used as an oil-in-water emulsifier and stable compositional regions were investigated as a function of polymer concentration and substitution degree. The viscosity of aqueous solutions of HHM-HEC increased drastically at lower concentration for HHM-HEC with a higher hydrophobic/hydrophilic substitution ratio. The intensity ratio of the first and third vibrational bands of pyrene (I(1)/I(3)) decreased with the increase of HHM-HEC concentration and the I(1)/I(3) reached a lower plateau at a lower concentration for HHM-HEC with a higher hydrophobic/hydrophilic substitution ratio. The concentration ranges of HHM-HEC solutions which stabilize O/W emulsions differ by the hydrophobic/hydrophilic substitution ratio. However the viscosity ranges of these HHM-HEC solutions were almost the same regardless of the hydrophobic/hydrophilic substitution ratio. At the suitable concentration range for emulsification, HHM-HEC networks have two properties: (1) oil particle retention capacity and (2) laxation which can trap emulsified particles.

Mechanism of oil-in-water emulsification using a water-soluble amphiphilic polymer and lipophilic surfactant.

A new O/W (oil-in-water) emulsification system was developed using the amphiphilic polymer HHM-HEC (hydrophobically-hydrophilically modified hydroxyethylcellulose) and a lipophilic surfactant. HHM-HEC was used as a thickener and polymeric surfactant, and the addition of small quantities of various types of nonionic lipophilic surfactant (hydrophilic-lipophilic balance <5) decreased the droplet size of several types of oil due to a lowering of the tension at the water/oil interface. The oil droplets were held by the strong network structure of the aqueous HHM-HEC solution, preserving the O/W phase without inversion. These stable O/W emulsions were prepared without the addition of hydrophilic surfactants and thus show improved water repellency.

Thickening properties and emulsification mechanisms of new derivatives of polysaccharides in aqueous solution.

The thickening properties of aqueous solutions of HHM-HEC (hydrophobically-hydrophilically modified hydroxyethylcellulose) and the emulsification mechanisms of HHM-HEC/water/oil systems were investigated. A dramatic increase in viscosity was observed with increased HHM-HEC concentration in water, caused by aggregation of hydrophobic alkyl chains. At higher concentrations of HHM-HEC (above 0.6 wt%) in water, it forms an elastic gel, which has good thixotropic properties and a high yield value. O/W (oil-in-water) type emulsions were obtained using HHM-HEC, which can emulsify various kinds of oil, including hydrocarbon, silicone, and perfluoropolymethylisopropyl ether. The viscosity of these emulsions depends only upon the oil volume fraction, not on the kind of oil. In addition, the oil particle size in the emulsions remained constant after a certain period because HHM-HEC formed a strong gel network structure and a protective layer, which prevented the emulsion from coalescing. Measurements of interfacial tension revealed that the alkyl chains in HHM-HEC did not significantly lower the interfacial tension at the water/oil interface when 0.5 wt% of HHM-HEC was added to water. Steady flow and oscillatory experimental results show that the rheological behavior of HHM-HEC/water/oil emulsions was similar to that of aqueous solutions of HHM-HEC. In the HHM-HEC/water/oil emulsion system, oil droplets were dispersed and kept stable in the strong gel structure of HHM-HEC. The aqueous solution of HHM-HEC showed salt resistance. It is thought to be due to sulfonic acid groups in HHM-HEC. The stability of the emulsion using HHM-HEC is based on both protective colloidal effects and associative thickening caused by alkyl chains in HHM-HEC.