Ethanol Rinse Research Articles

Influence of Post-Processing on the Degree of Conversion and Mechanical Properties of 3D-Printed Polyurethane Aligners.

This study explores how different post-processing methods affect the mechanical properties and degree of conversion of 3d-printed polyurethane aligners made from Tera Harz TC-85 resin. Using Fourier-transform infrared (FTIR) spectroscopy, the degree of conversion of liquid resin and post-processed materials was analyzed. This investigation focused on the effects of various post-curing environments (nitrogen vs. air) and rinsing protocols (centrifuge, ethanol, isopropanol, and isopropanol + water). The assessed mechanical properties were flexural modulus and hardness. The degree of conversion showed no significant variance across different groups, though the polymerization environment influenced the results, accounting for 24.0% of the variance. The flexural modulus varied considerably, depending on both the rinsing protocol and the polymerization environment. The standard protocol (centrifugation followed by nitrogen polymerization) exhibited the highest flexural modulus of 1881.22 MPa. Hardness testing revealed significant differences, with isopropanol treatments showing increased resistance to wear in comparison to the centrifuge and ethanol rinse treatments. This study conclusively demonstrates the adverse effects of oxygen on the polymerization process, underscoring the critical need for an oxygen-free environment to optimize material properties. Notably, the ethanol rinse followed by nitrogen polymerization protocol emerged as a viable alternative to the conventional centrifuge plus nitrogen method.

Anticariogenic action and safety profile of a cacao bean husk extract: A systematic review and meta-analysis

Nowadays, there is not a meta-analytic synthesis of the clinical reports that used a cacao bean husk extract (CBHE) solution as an anticariogenic mouth rinse. Thus, the aim of this study was to evaluate that information through a systematic review and meta-analysis methodology, conducted in accordance with PRISMA guidelines. Scientific databases were searched for studies published up to June 2021. Inclusion and exclusion criteria were applied to studies found and then, their data was analyzed. The five selected studies were categorized with a 36.6, 58.5, and 4.9 % of a low, unclear, and high risk of bias, respectively. Under appropriate heterogeneities (I2 values from 0 to 65 %, p values > 0.09) and absent reporting bias (symmetrical funnels), the meta-analyses show that the use of a CBHE mouth rinse reduced the salivary count of Streptococcus mutans (Z values from 2.45 to 10.61, p values < 0.01), similar to the chlorhexidine rinse performance (Z value= 0.55, p value= 0.58), and produced an insignificant presence of adverse events (Z value= 0.92, p value= 0.36) in children and adults, all these effects compared with those volunteers under an ethanol rinse or their pretest conditions. In conclusion, the CBHE mouth rinse reduced a cariogenic bacterium under an acceptable safety profile, but more clinical studies with high quality and more parameters are needed.

Influence of Postsynthesis Heat Treatment on Vapor-Phase-Polymerized Conductive Polymers.

The effect of thermal treatment on the structure and electrical/optical properties of vapor phase-polymerized poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:Tos) and polypyrrole:tosylate (PPy:Tos) polymer films was investigated. Thermal treatment was applied postpolymerization but prior to washing the embedded oxidant layer out of the polymer film. Structural and chemical changes arising from the treatment were studied in the context of their conductive and electrochromic behavior. Spectroscopic analysis indicated a rise in the doping levels of both conductive polymers when exposed to thermal treatment. Additionally, an increase in the film thickness was recorded after the oxidant and other unbound species were removed from the polymer layer using an ethanol rinse. As such, a strong indication that polymerization continued even in the absence of (external) monomer vapor was present. This film thickness increase was most pronounced for PPy:Tos but also present in the PEDOT:Tos film. Heat-treated films exhibited enhanced cohesion, making them more robust and therefore increasing the viability for the material to be used in the optoelectronics area. This robustness, due to additional (cross-linking) oligomer growth, came at the expense of lower conductivity relative to their untreated counterparts.

Effect of Proteolytic Agents on Microleakage of Etch and Rinse Adhesive Systems

Objective: this study aimed to assess the effect of treatment of phosphoric acid etched dentin surface with 5% bromelain enzyme and Nd:YAG laser prior to the use of etch and rinse adhesive systems on microleakage margins of class V composite restorations. Materials and Methods: sixty sound premolar teeth were selected. Standard class V cavities were prepared in the buccal and lingual surfaces of each teeth. Preparation in that way 1 mm of the cavity was above and 1 mm of it was below the cementoenamel junction. The teeth were then randomly divided into three groups including 20 teeth(40cavities in each gorup). Two ethanol base etch and rinse system (Adper Single Bond and OptiBond Solo) was applied in each group. In the control group, cavities were etched with 37% phosphoric acid. Adper Single Bond was applied to 20 and OptiBond Solo was applied to the remaining 20 cavities and they were restored with Z250 composite (n=40). The same procedures were performed in bromelain and Nd:YAG laser groups with the difference that prior to the application of adhesive, aqueous 5% bromelain was applied in bromelain group while Nd:YAG laser was irradiated in laser group. All teeth were thermocycled and their apices were sealed with sticky wax. The tooth surfaces were coated with nail varnish except for 1 mm around the restoration margins, and the teeth were then immersed in fuchsine and sectioned by a diamond disc into mesial and distal halves. Marginal microleakage at both sides was determined and scored under a stereomicroscope at x40 magnification. Then data were analyzed using the Kruskal Wallis and Mann Whitney tests (α=0.05). Results: according the result of Mann Whitney test, Cervical margins showed significantly higher microleakage than the occlusal margins (P=0.000) but no significant difference was noted in microleakage of occlusal (P=0.362) or gingival (P=0.147) margins among the three groups by Kruskal Wallis test. Conclusion: in conclusion, application of proteolytic agents(5% bromelain solution and Nd:YAG laser) on acid-etched dentin surface prior to the application of adhesive has no significant effect on marginal microleakage of class V composite restorations.

Deactivation mechanism of beta-zeolite catalyst for synthesis of cumene by benzene alkylation with isopropanol

Abstract The alkylation of benzene with isopropanol over beta-zeolite is a more cost-effective solution to cumene production. During the benzene alkylation cycles, the cumene selectivity slowly increased, while the benzene conversion presented the sharp decrease due to catalyst deactivation. The deactivation mechanism of beta-zeolite catalyst was investigated by characterizing the fresh and used catalysts. The XRD, SEM and TEM results show that the crystalline and particle size of the beta-zeolite catalyst almost remained stable during the alkylation cycles. The drop in catalytic activity and benzene conversion could be explained by the TG, BET, NH 3 -TPD and GC–MS results. The organic matters mainly consisted of ethylbenzene, p -xylene and 1-ethyl-3-(1-methyl) benzene produced in the benzene alkylation deposited in the catalyst, which strongly reduced the specific surface area of beta-zeolite catalyst. Moreover, during the reaction cycles, the amount of acidity also significantly decreased. As a result, the catalyst deactivation occurred. To maintain the catalytic performance, the catalyst regeneration was carried out by using ethanol rinse and calcination. The deactivated catalyst could be effectively regenerated by the calcination method and the good catalytic performance was obtained.

Get the most out of blow hormones: validation of sampling materials, field storage and extraction techniques for whale respiratory vapour samples.

Studies are progressively showing that vital physiological data may be contained in the respiratory vapour (blow) of cetaceans. Nonetheless, fundamental methodological issues need to be addressed before hormone analysis of blow can become a reliable technique. In this study, we performed controlled experiments in a laboratory setting, using known doses of pure parent hormones, to validate several technical factors that may play a crucial role in hormone analyses. We evaluated the following factors: (i)practical field storage of samples on small boats during daylong trips; (ii)efficiency of hormone extraction methods; and (iii)assay interference of different sampler types (i.e. veil nylon, nitex nylon mesh and polystyrene dish). Sampling materials were dosed with mock blow samples of known mixed hormone concentrations (progesterone, 17β-estradiol, testosterone, cortisol, aldosterone and triiodothyronine), designed to mimic endocrine profiles characteristic of pregnant females, adult males, an adrenal glucocorticoid response or a zero-hormone control (distilled H2O). Results showed that storage of samples in a cooler on ice preserved hormone integrity for at least 6 h (P=0.18). All sampling materials and extraction methods yielded the correct relative patterns for all six hormones. However, veil and nitex mesh produced detectable assay interference (mean 0.22±0.04 and 0.18±0.03 ng/ml, respectively), possibly caused by some nylon-based component affecting antibody binding. Polystyrene dishes were the most efficacious sampler for accuracy and precision (P<0.001), but required an ethanol rinse for improved progesterone recovery (increased 81%; P<0.001). Awareness of assay interference from exogenous materials is crucial to future studies. This study establishes critical groundwork to help ensure that hormones can be measured accurately in samples obtained from field collections of whale blow.

Effect of various sterilization procedures on the in vitro germination of cotton seeds

In vitro manipulations of cotton often require high-quality sterile seedlings as a source of hypocotyl and cotyledon explants for initiation of embryogenic cultures or embryo apexes for shoot production. Unfortunately, in vitro seed germination is often hindered if cotton seeds were collected from the open field and stored under improper conditions. In our case a limited supply of field-grown cotton seeds was received, which necessitated the development of a more effective surface sterilization protocol. Seeds from two accessions, designated as I and II, with very high contamination levels and lowered germination rate were used in this study. These seeds were treated with the most commonly used sterilizing agents, which included commercial bleach, chlorine gas and hydrogen peroxide. Additional steps such as soap-water washes (SW), 70 % ethanol (ETH) and plant preservative mixture rinses were also included in the sterilization procedures to improve the efficiency of tested protocols. Surface sterilized seeds were germinated on Linsmaier and Skoog medium and the percentage of contamination free and well-germinated seeds were recorded for each treatment. Seeds treated with hydrogen peroxide showed significant improvement in germination rate and level of contamination when compared to identical seeds treated with chlorine gas and commercial bleach. The most effective sterilization protocol for all genotypes tested consisted of SW wash followed by ETH rinse and H2O2 sterilization for 7 h. This protocol was successfully used to sterilize seeds of 55 cotton lines.

An “off-the-shelf” capillary microfluidic device that enables tuning of the droplet breakup regime at constant flow rates

The fabrication of glass capillary microfluidic devices is technically challenging, often hampering use of the design. We describe a new technique, based on commercially available components, for assembling flow focusing capillary devices that can readily be taken apart and cleaned between uses. This design strategy allows for generation of both water-in-oil and oil-in-water emulsions in the same device after an ethanol rinse. The modularity of the device enables the adjustment of the tip separation between the two inner capillaries during droplet generation, which enables tuning of the age of the interface. Time-dependent surfactant diffusion to the interface changes the interfacial tension, thus providing an approach for adjusting the capillary number in addition to the usual method of changing flow rates. This design enables the tuning of the mode of breakup and the droplet size.

Depletion of water molecules during ethanol wet-bonding with etch and rinse dental adhesives

The treatment of demineralized dentin with ethanol has been proposed as a way to improve hydrophobic monomer penetration into otherwise water saturated collagen fibrils. The ethanol rinse is expected to preserve the fibrils from collapsing while optimizing resin constituent infiltration for better long term adhesion. The physico-chemical investigations of demineralized dentin confirmed objectively these working hypotheses. Namely, Differential Scanning Calorimetry (DSC) measurements of the melting point of water molecules pointed to the presence of free and bound water states. Unfreezable water was the main type of water remaining following a rinsing step with absolute ethanol. Two different liquid water phases were also observed by Magic Angle Spinning (MAS) solid state Nuclear magnetic Resonance (NMR) spectroscopy. Infrared spectra of ethanol treated specimens illustrated differences with the fully hydrated specimens concerning the polar carbonyl vibrations. Optical microscopy observations as well as scanning electron microscopy showed an improved dentin-adhesive interface with ethanol wet bonding. The results indicate that water can be confined to strongly bound structural molecules when excess water is removed with ethanol prior to adhesive application. This should preserve collagen from hydrolysis upon aging of the hybrid layer.

Effect of rinsing with ethanol-containing mouthrinses on the production of salivary acetaldehyde

It has been suggested that the use of alcohol-containing mouthrinses could lead to the presence of acetaldehyde in saliva. In this cross-over study, salivary acetaldehyde levels and microbial profiles were determined before and after rinsing with ethanol-containing mouthrinses with essential oils (EO) and cetyl pyridinium chloride (CPC) as the active ingredients, and with 21.6% ethanol and water controls. After rinsing with all ethanol-containing rinses, acetaldehyde was detected in saliva after 30 s but declined to low levels after 5 min. The highest peak levels were seen with the ethanol control (median = 82.9 μM at 2 min) and were significantly higher than those seen at the same time after rinsing with the EO rinse (43.1 μM). There was no correlation between microbial counts or plaque scores and acetaldehyde levels, although dividing the subjects on the basis of a peak acetaldehyde salivary concentration of > 90.8 μM after the ethanol rinse revealed that the high responders were highly significantly more likely to harbour salivary yeasts than were the low responders. Rinsing with ethanol-containing mouthrinses causes a rapid, but transient, increase in salivary acetaldehyde levels.

Separation of ethanol–water liquid mixtures by adsorption on silicalite

The separation of ethanol–water mixtures with ethanol-selective adsorbents by cyclic multi-column adsorption processes, such as concentration swing adsorption (CSA) or concentration thermal swing adsorption (CTSA), is attractive because practically pure ethanol can be obtained with high recovery and low energy requirement. In this work, the adsorption of ethanol–water liquid mixtures on a column packed with silicalite pellets has been studied. A theoretical model for predicting the column dynamics in this system has been developed, taking into account the effect of the mass transfer resistance in the whole concentration range (between 1 and 100% ethanol). The model, based on conservation equations, has been validated with experimental data obtained in a laboratory column. Experimental data on the column dynamics of the displacement of water by pure ethanol (the so-called ethanol rinse step in CSA or CTSA) are presented, which are not available in the literature. This displacement is required to recover fuel grade ethanol when the column is regenerated. An important mass transfer resistance has been found in the ethanol rinse step, resulting in low separation efficiency when CSA or CTSA cycles are applied to the studied system. The inclusion of a new step is proposed to overcome this problem. The developed model has been employed to estimate the performance of the modified cycle for separating an 8% ethanol–water mixture, and the results show that it can produce practically pure ethanol (>99.5% in weight) with high recovery (above 95%).

Effect of ethanol application on post‐luting to intraradicular dentine

To examine the effect of the application of an ethanol rinse before luting fibre posts to intraradicular dentine with etch-and-rinse adhesive systems by means of push-out bond strength evaluation and scanning electron microscopic (SEM) analysis. Fibre posts were luted to single-canal premolars using Dual Link as a luting agent in combination with a three-step (All Bond 2) or a two-step (One Step Plus) etch-and-rinse adhesive system, which were applied as per manufacturers' instructions (control) or with the additional rinse of ethanol on acid-etched dentine prior to the bonding procedures (experimental). Bonded specimens were sectioned into 1-mm-thick slabs and subjected to push-out bond strength testing. In addition, specimens from each group were processed for SEM analysis. Data were analysed by Kruskal-Wallis followed by Dunn's post hoc test at P = 0.05. Push-out bond strength of All Bond 2 was significantly increased if the adhesive was applied on ethanol-saturated dentine (P < 0.05), whilst no significant difference (P > 0.05) was detected amongst experimental and control groups for One Step Plus. Irrespective of the adhesive, the SEM analysis revealed good impregnation patterns when both bonding techniques were employed. The use of the additional ethanol rinse on acid-etched dentine revealed higher bond strength of All Bond 2 when compared with the control application procedure, used in combination with a resin-based cement to lute fibre posts into the dowel space. However, no bond strength improvements were detected using One Step Plus. Further investigations are needed to develop a clinically applicable ethanol/bonding/luting technique.

Low-temperature Fabrication of a Crystallized Si Film Deposited on a Glass Substrate using an Yttria-stabilized Zirconia Seed Layer

AbstractWe have been investigating fabrication of a crystallized Si (c-Si) film deposited on a glass substrate at low temperature, using a poly-yttria-stabilized zirconia (poly-YSZ) film as a seed layer. It can be expected that the crystallographic information of the YSZ layer transmits to the deposited Si film so that it stimulates its crystallization even at lower temperature. To reduce the crystallization temperature further, we focused on the surface treatment of the YSZ layer, in which it was dipped in the HF solution, followed by rinsing with deionized water (DIW) or with ethanol.After depositing the poly-YSZ layer by reactive magnetron sputtering on the quartz glass substrate, the Si film was deposited directly on it by e-beam vacuum evaporation in &lt;10-6 Pa. The Raman spectra of the Si films deposited at 430 °C on the ethanol-rinsed glass without YSZ layer and on the DIW-rinsed YSZ layer showed amorphous phase. However, on the ethanol-rinsed YSZ layer, they showed a strong peak of c-Si of the deposited film, even at 350 °C, and indicated the beginning of the crystallization at 320 °C. This means that the YSZ layer enhanced the Si film crystallization, and that the ethanol-rinse was effective for low-temperature crystallization. The crystalline fraction of the Si film varied with the yttria content and the surface treatment of the YSZ layer prior to the Si film deposition. From the XPS results, we found out that fluorine F were adsorbed on the surface and were bonded with the Y. The Y 3d and F 1s peaks observed from the ethanol-rinsed YSZ were higher than those of the DIW rinse, which suggests that the Y and adsorbed F on the surface were removed by the DIW rinse, but remained even after the ethanol rinse. Based on the Raman and XPS results, we can speculate that the excessive amount of F on the YSZ layer surface prior to the Si film deposition play an important role on the Si film crystallization. We observed the surface of the Secco-etched Si/YSZ films deposited at 320, 350, and 430 °C by SEM. The number of crystallized Si grains was denser at higher temperature than that of lower temperature. That is, the Si film deposited at 430 °C was crystallized thoroughly on the whole substrate, but some regions of the Si films deposited at 350 and 320 °Cwere amorphous and removed by the Secco etching. The grain sizes were in the range from 20 to 40 nm, and the size at the lower deposition temperature was more uniform than the higher temperature. From SIMS observation, it was found that Zr atoms diffuse from the interface with the YSZ layer.

Effect of Ethanol Rinse, Lactobacillus fermentum Inoculation, and Modified Atmosphere on Ground Chicken Meat Quality

Ground chicken breast meat was prepared using combinations of the following treatments: ethanol rinse before grinding, inoculation with Lactobacillus fermentum after grinding, and modified atmosphere packaging in either 90% O(2) and 10% CO(2) or 90% N(2) and 10% CO(2). Control treatments included water rinse and noninoculation with L. fermentum. Packaged meat was refrigerated and sampled for various shelf-life quality indices on d 0, 3, and 6. The inoculation with L. fermentum had little or no effect on ground meat shelf life. The ethanol-rinsed meat had lower off-odor scores and lower microbial growth compared to nonethanol rinsed meat. The high-N(2) atmosphere maintained meat color better than the high-O(2) packaging, but there was no effect on microbial growth. The combination of ethanol rinsing and high-N(2) packaging extended ground chicken quality compared with meat rinsed in water and packaged in high O(2).

Getting Epoxy Semi-Thin Sections to Stick to Glass Slides

Abstract Semi-thin sections don't always want to stick to glass slides, but subbing slides is usually not needed. For sections about 2 μm thick and no larger than 4 mm on a slide, this simple method works well for me: 1) Clean 1x3 inch glass slides with an ethanol rinse, then air dry at room temperature or blow down with a hair dryer. 2) Collect sections on a drop or two of distilled water on the slide, transferred there from the microtome with a clean fine tipped artists brush. Collect about 8-12 sections per drop. 3) Warm the slide beneath the water drop from below using an alcohol lamp, fairly hot, but not to boil, of course. After drying by heating the sections stick quite well. 4) Stain, usually with 0.2 μm filtered toluidine blue, again heating but gently this time, for about a minute, until stain “develops” the section. 5) Rinse that stain off with distilled water from a squirt bottle, even directing the spray right onto the sections to get rid of any precipitate. Dry again gently with flame. The heating is the trick. There should not be any need for subbing or otherwise treating slides other than cleaning them.

A Solid‐Phase Microextraction Chamber Method for Analysis of Manure Volatiles

Odors from livestock operations are a complex mixture of volatile carbon, sulfur, and nitrogen compounds. Currently, detailed volatiles analysis is both time consuming and requires specialized equipment and methods. This work describes a new method that utilizes a dynamic flux chamber, solid-phase microextraction (SPME), and gas chromatography-mass spectroscopy (GC-MS) to describe and compare the odorous compounds emitted from cattle and swine feces. Evaluation of method parameters produced a protocol for comparing relative emissions based on fixed sample temperature (20 degrees C) and exposed surface area (approximately 523 cm(2)), air flow rates (1 L min(-1) or 16 cm s(-1)), SPME exposure time (5 min), and chamber cleaning procedures (70% ethanol rinse and drying for 30 min at 105 degrees C) to minimize cross-contamination between samples. A variety of volatile organic compounds (VOCs) including alcohols, volatile fatty acids, aromatic ring compounds, ketones, esters, and sulfides were routinely detected and the relative emissions from fresh and incubated (37 degrees C overnight) swine and cattle feces were compared as a measure of potential to produce odorants during manure storage. Differences in the types and relative quantities of volatiles emitted were detected when animal species (cattle or swine), diet, fecal incubation, or sample storage conditions (20, 4, or -20 degrees C) were varied.

Influence of CMP Chemicals on the Properties of Porous Silica Low-k Films

This paper describes the influence of the chemical mechanical polishing (CMP) process on the degradation in the leakage currents and dielectric constants of porous silica low- films. It is found that the leakage current and dielectric constant increased by post-CMP cleaning solution due to the increase of and bonds according to Fourier transform infrared (FTIR) absorption. This is because the surfactant in the post-CMP cleaning solution permeated into the porous silica. The permeated surfactant in the porous silica can be removed by rinsing with 2-propanol or ethanol after the CMP process. Degradations of the leakage current density and dielectric constant can be recovered by ethanol rinse and subsequent 1,3,5,7-tetramethyl-cyclo-tetrasiloxane vapor treatment, which makes the pore wall surfaces hydrophobic.

TASTE RESPONSES TO MONOSODIUM GLUTAMATE AFTER ALCOHOL EXPOSURE

The aim of the present study was to evaluate the effects of acute and chronic exposure to alcohol on taste responses to a prototypic umami substance, monosodium glutamate (MSG). The rated intensity and pleasantness of MSG taste (0.03-10.0%) was compared in chronic male alcoholics (n = 35) and control subjects (n = 25). In a separate experiment, the effects of acute exposure of the oral mucosa to ethanol rinse (0.5-4.0%) on MSG taste (0.3-3.0%) were studied in 10 social drinkers. The alcoholic and control group did not differ in terms of the rated intensity and pleasantness of MSG taste. Electrogustometric thresholds were significantly (P < 0.01) higher, i.e. worse, in the alcohol-dependent subjects. The difference remained significant after controlling for between-group differences in cigarette smoking and coffee drinking. Rinsing with ethanol did not alter either intensity or pleasantness of MSG taste in social drinkers. The present results suggest that: (i) neither acute nor chronic alcohol exposure modifies taste responses to MSG; (ii) alcohol dependence may be associated with deficit in threshold taste reactivity, as assessed by electrogustometry.

Quartz crystal microbalance and infrared reflection absorption spectroscopy characterization of bisphenol A absorption in the poly(acrylate) thin films.

The absorption process of bisphenol A (BPA) in a number of poly(acrylate) thin films, such as poly(2-methoxyethyl acrylate) (PMEA), poly(ethyl acrylate) (PEA), poly(n-butyl methacrylate) (PBMA), and poly(methyl methacrylate) (PMMA), has been investigated by quartz crystal microbalance (QCM) and infrared reflection absorption spectroscopy (IRRAS) measurements. Both QCM and IRRAS measurements show that the BPA molecules absorb in PMEA, PEA, and PBMA thin films but not in PMMA thin film. The differences in the BPA absorption behavior are mainly attributed to the difference in the glass transition temperature (T(g)) between these polymers. This absorption behavior also depends on the BPA concentration and polymer film thickness. Furthermore, IRRAS characterization demonstrates that the hydrogen bonding is formed between the hydroxyl group in BPA and the carbonyl group in the poly(acrylate) thin films. BPA molecule absorbed in these polymer thin films can be removed by ethanol rinse treatment. By optimizing experimental conditions for the QCM electrode modified by PMEA thin film, detection limitation of approximately 1 ppb for BPA can be realized by the in situ QCM measurement. This method is expected to be a sensitive in situ detection way for trace BPA in the environmental study.

Residual ethanol content of donor sclera after storage in 95% ethanol and saline rinse of various durations

PURPOSE : Some surgeons are wary of using alcohol-preserved sclera for allografts because they fear a toxic effect on surrounding tissue after placement. We set out to determine the amount of ethanol remaining in scleral allograft material after storage in 95% ethanol. METHODS : Sixty half scleras from 30 donors were preserved in 95% ethanol for an average of 31 ± 14 days (range, 11 to 50 days). Rehydration was performed by soaking each half sclera in 4 ounces of balanced salt solution. Half scleras were randomly assigned to six groups of 10 each. Assays for ethanol were performed on the following groups: no balanced salt solution soak and balanced salt solution soak for 10 minutes, 20 minutes, 30 minutes, 40 minutes, and 50 minutes. Ethanol assay was performed by Headspace Gas Space Chromatography at ChemaTox Laboratory, Inc, Boulder, Colorado. RESULTS : The 10 half scleras without balanced salt solution soak had a mean (± SD) ethanol level of 175 ± 14.1 mg per g of sclera. After 10 minutes of balanced salt solution soak, the level decreased to 7.57 ± 1.56 mg per g, then 3.77 ± 3.02 mg per g at 20 minutes, 1.59 ± 0.61 mg per g at 30 minutes, 1.07 ± 0.30 mg per g at 40 minutes, and 0.96 ± 0.26 mg per g at 50 minutes. Approximately 96% of the ethanol is leeched out of the half sclera by 10 minutes and 98% by 20 minutes. CONCLUSIONS : For sclera preserved in 95% ethanol, soaking in balanced salt solution for 20 minutes or longer leeches approximately 98% of the ethanol from the preserved donor sclera.