An Evaluation of Three Biological Indicator Systems in Flash Sterilization

1987 ◽  
Vol 8 (8) ◽  
pp. 311-316 ◽  
Author(s):  
Helen Rosen Kotilainen ◽  
Nelson M. Gantz
Keyword(s):  
Exposure Time ◽  
Color Change ◽  
Biological Indicators ◽  
Biological Indicator ◽  
The Other ◽  
Minute Exposure ◽  
Color Changes ◽  
Indicator Systems

AbstractAn evaluation of two flash-sterilization-specific biological indicators (BI) and a traditional spore strip indicator was performed to assess sensitivity and reliability as reflected in survive/kill ratios. The Bis tested included: 3M's Attest® #1261, Amsco's Proof Flash™, and Castle® Tec Test. Survival after “come-up” time alone, (0 exposure) and one-, two-, and three-minute exposures at 273°F in a gravity displacement sterilizer was measured by media color change or turbidity after incubation at 55°C. Each cycle was replicated three times on two separate days with six of each BI per run. Positive Bis were subcultured as necessary. Proof Flash presented technical difficulties due to incomplete or impossible crushing of media vials, unexpected media color changes, and evaporation of media. Tec Test was not sufficiently resistant as survivors were not detected at any exposure time. The Attest had 100% survival at zero and one-minute exposures and 94% survival after the two-minute exposure. No survivors were detected after the three-minute exposure. Although each institution should evaluate Bis for their own use independently, the data indicate that Attest #1261 monitored the three-minute flash cycles more satisfactorily than the other Bis tested.

Comparison of a Rapid Readout Biological Indicator for Steam Sterilization With Four Conventional Biological Indicators and Five Chemical Indicators

1996 ◽  
Vol 17 (7) ◽  
pp. 423-428 ◽  
Author(s):  
William A. Rutala ◽  
Suzanne M. Jones ◽  
David J. Weber
Keyword(s):  
Exposure Time ◽  
Color Change ◽  
Biological Indicators ◽  
Biological Indicator ◽  
Failure Rates ◽  
Steam Sterilization ◽  
Chemical Indicators

AbstractObjective:In this study, we compare a new biological indicator that provides results within 3 hours with four conventional, 48-hour biological indicators and five chemical indicators.Design:Biological indicators tested included the conventional Attest 1262, Proof Plus, Assert, and Biosign, and the new Attest 1292 Rapid Readout biological indicator. Chemical indicators tested included Comply, Propper, Chemdi, Sterigage, and Thermalog S. Spore survival following 121°C in a gravity displacement sterilizer was measured by media color change after incubation for 24 and 48 hours at 56°C for the conventional biological indicators, fluorescence at 3 hours for the Attest 1292 Rapid Readout biological indicator, and color change for the chemical indicators. Each exposure time was replicated 12 times with five samples of each indicator per run (ie, 60 replicates per indicator).Results:At 48 hours, the conventional biological indicators Attest 1262, Proof Plus, Assert, and Biosign showed 100%, 95%, 88%, and 93% spore survival at 5 minutes' exposure; 0%, 0%, 0%, and 8% at 10 minutes; and all showed 0% survival at 15 minutes' exposure. Following a 3hour incubation, the Attest 1292 Rapid Readout biological indicator showed fluorescence at 100%, 72%, and 0% at 5, 10, and 15 minutes, respectively. The chemical indicators Comply, Propper, Chemdi, Sterigage, and Thermalog S revealed sterilization failure rates of 100%, 100%, 100%, 100%, and 100% at 5 minutes' exposure; 0%, 0%, 0%, 92%, and 100% at 10 minutes; and, 0%, 0%, 0%, 3%, and 27% at 15 minutes' exposure, respectively.Conclusions:The sensitivity of the Attest 1292 Rapid Readout biological indicator parallels that of conventional biological indicators. These data suggest that a 3hour rapid readout biological indicator is equivalent to a standard 48-hour biological indicator. Some chemical indicators (eg, Thermalog S) failed to indicate adequate sterilization at 15 minutes' exposure. These chemical indicators have the potential of causing unnecessary recall of adequately sterilized items.

Evaluation of a Rapid Readout Biological Indicator for Flash Sterilization with Three Biological Indicators and Three Chemical Indicators

1993 ◽  
Vol 14 (7) ◽  
pp. 390-394 ◽  
Author(s):  
William A. Rutala ◽  
Maria F. Gergen ◽  
David J. Weber
Keyword(s):  
Enzyme Activity ◽  
Bacillus Stearothermophilus ◽  
Color Change ◽  
Safety Margin ◽  
Biological Indicators ◽  
Biological Indicator ◽  
Processing Conditions ◽  
Fluorescent Product ◽  
Chemical Indicators ◽  
Chemical Indicator

AbstractObjective:Flash sterilization is most commonly used for emergency sterilization of unwrapped items in a gravity displacement sterilizer for three minutes. Sterilization quality assurance is monitored by biological indicators that require a 24-hour incubation prior to reading. In this study, we compared a new biological indicator that provides results within 60 minutes with three conventional, 24-hour biological indicators for monitoring flash sterilization and three chemical indicators.Design:Conventional biological indicators tested included the conventional Attest 1261, Proof Flash and Assert, while the rapid readout indicator tested was Attest 1291. Attest Rapid Readout detects the presence of aBacillus stearothermophilusenzyme by reading a fluorescent product that is produced by the enzymatic break-down of a nonfluorescent substrate. Chemical indicators tested included Comply, Incheque, and Thermalog S. Survival at 132°C in a gravity displacement sterilizer was measured by media color change after incubation for 24 hours at 56°C for the three conventional biological indicators, fluorescence at 60 minutes for the Attest Rapid Readout biological indicator, and color change for the chemical indicators. Each exposure time was replicated four times with 10 of each biological and chemical indicator per run.Results:The conventional biological indicators (Attest, Proof Flash, and Assert) had 90%, 48%, and 40% spore survival at two minutes exposure; 23%, 3%, and 0% at three minutes exposure; and 3%, 0%, and 0% at four minutes exposure respectively. The Attest Rapid Readout biological indicator had 88%, 33%, and 0% enzyme activity detectable at 2, 3, and 4 minutes exposure. The chemical indicators Comply, Incheque, and Thermalog S revealed sterilization failure rates of 100%, 100%, and 100% at 0 minutes exposure; 100%, 100%, and 45% at one minute; 0%, 0%, and 28% at two minutes exposure; 0%, 0%, and 18% at three minutes exposure; and 0%, 0%, and 0% at four minutes exposure, respectively.Conclusion:The sensitivity of the Attest Rapid Readout parallels the conventional biological indicators. These data suggest that a 60-minute rapid readout biological indicator is equivalent to the 24-hour biological indicators. If further studies demonstrate that a four-minute flash sterilization cycle provides a needed safety margin to ensure sterilization, then consideration should be given to requiring a four-minute flash sterilization cycle. Chemical indicators were too sensitive to the processing conditions (eg, steam) and are inadequate to ensure adequate sterilization.

scholarly journals The Effects of Natural Weathering on Color Stability of Impregnated and Varnished Wood Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Turkay Turkoglu ◽  
Ergun Baysal ◽  
Hilmi Toker
Keyword(s):  
Scots Pine ◽  
Color Change ◽  
Color Stability ◽  
The Other ◽  
Natural Weathering ◽  
Color Changes ◽  
Oriental Beech ◽  
Total Color Change ◽  
Dark Color ◽  
Copper Arsenate

The aim of this study was to investigate effects of natural weathering on color stability of Scots pine (Pinus sylvestrisL.) and Oriental beech (Fagus orientalisL.) impregnated with some chemicals [tanalith-E (TN-E), adolit-KD5 (AD-KD5), and chromated copper arsenate (CCA)] and then varnished [synthetic varnish (SV) and polyurethane varnish (PV)]. While applying varnish increased lightness, impregnation decreased lightness of the wood specimens before natural weathering. Natural weathering caused greenish, bluish, and dark color tones of the wood surface. Total color change was increased with increasing exposure times in natural weathering. Untreated (control) wood specimens exhibited higher color changes than the other wood specimens in all the stages of natural weathering. The total color changes of untreated Oriental beech specimens were less than untreated Scots pine specimens. The color stability of impregnated and varnished wood specimens gave better results than untreated and solely varnished wood specimens after natural weathering. The best color stability was obtained from both Oriental beech and Scots pine wood impregnated with TN-E before PV coating.

scholarly journals The effect of the thermoplastic nilon enterprises (valplast) on clove extract (syzygium aromaticum) in various concentrations on the color change

2017 ◽  
Vol 2 (3) ◽  
pp. 180
Author(s):  
Niken Wibawaningtyas ◽  
Dewi Kristiana ◽  
Niken Probosari
Keyword(s):  
Light Intensity ◽  
Sample Size ◽  
Color Change ◽  
The Other ◽  
Syzygium Aromaticum ◽  
Test Results ◽  
Color Changes ◽  
Flower Extract ◽  
Significant Difference ◽  
One Way Anova

Objective: To investigate the effect of soaking of thermoplastic nylon (valplast) on clove flower extract (syzygium aromaticum) as a denture cleanser with different concentration 0.8%, 1%, 1.2%, 1.4%, and 1.6% to the color change of thermoplastic nylon.Material and Methods: 30 samples were divided into 6 groups. The sample size is (10x10x1) mm. The first group was immersed in sterile aquades and the other groups were immersed in clove flower extracts of 0.8%, 1%, 1.2%, 1.4%, and 1.6% for 12 days. The light intensity then measured using densitometer.Results: One way anova test results obtained value 0.174 (p>0.05) which indicates that there is no significant difference in each group.Conclusions: This study are darker discoloration of the thermoplastic nylon at a concentration of 1.6% and lower color changes occurring at a concentration of 0.8%.

Povidone-Iodine 3-Minute Exposure Time is Viable in Preparation for Cataract Surgery

2017 ◽  
Vol 27 (5) ◽  
pp. 573-576 ◽  
Author(s):  
Chu L. Nguyen ◽  
Lawrence J. Oh ◽  
Eugene Wong ◽  
Ian C. Francis
Keyword(s):  
Clinical Practice ◽  
Cataract Surgery ◽  
Exposure Time ◽  
Ocular Surface ◽  
Povidone Iodine ◽  
Bacterial Load ◽  
Minute Exposure ◽  
Visual Outcomes ◽  
Preoperative Prophylaxis ◽  
Operating Room Staff

Purpose Povidone-iodine (PI) is widely used to reduce the preoperative conjunctival bacterial load. This study aimed to evaluate the employment of PI 10% in an attempt to sterilize the ocular surface prior to cataract surgery, and to show that PI could be left in contact for 3 minutes. The viability of this exposure time in clinical practice, associated adverse events, and visual outcomes were documented. Methods In this prospective cohort study, phacoemulsification cataract surgery was performed in 604 patients by a single surgeon. Preoperative preparation was undertaken with PI 10%, applied to the cornea, conjunctival sac, eyelids, and periorbital skin with sterile cotton gauze. Povidone-iodine was then flushed onto the ocular surface. Operating room staff timed the precise duration of exposure. After the 3-minute preparation, the lids were thoroughly dried with fresh dry gauze. Results The median PI exposure time was 3.17 minutes, with an interquartile range of 0.25. All cases were followed up postoperatively at 1 day, 1 week, and 1 month. There were no complications attributable to PI. Visual outcomes were satisfactory. Conclusions Implementation of a preoperative prophylaxis protocol that used PI 10% with a 3-minute exposure time can be performed in clinical practice. The 3-minute exposure time had no adverse sequelae.

scholarly journals Investigation of the selective color-changing mechanism of Dynastes tityus beetle (Coleoptera: Scarabaeidae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiyu Sun ◽  
Wei Wu ◽  
Limei Tian ◽  
Wei Li ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Color Change ◽  
Incidence Angle ◽  
Ion Beam ◽  
Three Dimensional ◽  
Water Infiltration ◽  
Photonic Materials ◽  
Local Color ◽  
Water Contact ◽  
Color Changes

AbstractNot only does the Dynastes tityus beetle display a reversible color change controlled by differences in humidity, but also, the elytron scale can change color from yellow-green to deep-brown in specified shapes. The results obtained by focused ion beam-scanning electron microscopy (FIB-SEM), show that the epicuticle (EPI) is a permeable layer, and the exocuticle (EXO) is a three-dimensional photonic crystal. To investigate the mechanism of the reversible color change, experiments were conducted to determine the water contact angle, surface chemical composition, and optical reflectance, and the reflective spectrum was simulated. The water on the surface began to permeate into the elytron via the surface elemental composition and channels in the EPI. A structural unit (SU) in the EXO allows local color changes in varied shapes. The reflectance of both yellow-green and deep-brown elytra increases as the incidence angle increases from 0° to 60°. The microstructure and changes in the refractive index are the main factors that influence the process of reversible color change. According to the simulation, the lower reflectance causing the color change to deep-brown results from water infiltration, which increases light absorption. Meanwhile, the waxy layer has no effect on the reflection of light. This study lays the foundation to manufacture engineered photonic materials that undergo controllable changes in iridescent color.

scholarly journals Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2569
Author(s):  
Mia Kurek ◽  
Nasreddine Benbettaieb ◽  
Mario Ščetar ◽  
Eliot Chaudy ◽  
Maja Repajić ◽  
...  
Keyword(s):  
Food Packaging ◽  
Water Solubility ◽  
Color Change ◽  
Chitosan Film ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Color Changes ◽  
Insoluble Particles ◽  
Polymer Stability ◽  
Food Packaging Films

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging.

RADIATION EXPOSURE TO THE BACK WITH DIFFERENT TYPES OF APRONS

2021 ◽  
Author(s):  
Seung Wan Hong ◽  
Tae Won Kim ◽  
Jae Hun Kim
Keyword(s):  
Radiation Exposure ◽  
Effective Dose ◽  
Exposure Time ◽  
The Other ◽  
Lead Apron ◽  
Type Group ◽  
Air Kerma ◽  
Different Types ◽  
The Relationship

Abstract Physicians and nurses stand with their back towards the C-arm fluoroscope when using the computer, taking things out of closets and preparing drugs for injection or instruments for intervention. This study was conducted to investigate the relationship between the type of lead apron and radiation exposure to the backs of physicians and nurses while using C-arm fluoroscopy. We compared radiation exposure to the back in the three groups: no lead apron (group C), front coverage type (group F) and wrap-around type (group W). The other wrap-around type apron was put on the bed instead of on a patient. We ran C-arm fluoroscopy 40 times for each measurement. We collected the air kerma (AK), exposure time (ET) and effective dose (ED) of the bedside table, upper part and lower part of apron. We measured these variables 30 times for each location. In group F, ED of the upper part was the highest (p < 0.001). ED of the lower part in group C and F was higher than that in group W (p = 0.012). The radiation exposure with a front coverage type apron is higher than that of the wrap-around type and even no apron at the neck or thyroid. For reducing radiation exposure to the back of physician or nurse, the wrap-around type apron is recommended. This type of apron can reduce radiation to the back when the physician turns away from the patient or C-arm fluoroscopy.

Influence of Hydrogen Peroxide Bleaching Gels on Color, Opacity, and Fluorescence of Composite Resins

2012 ◽  
Vol 37 (5) ◽  
pp. 526-531 ◽  
Author(s):  
CRG Torres ◽  
CF Ribeiro ◽  
E Bresciani ◽  
AB Borges
Keyword(s):  
Hydrogen Peroxide ◽  
Composite Resin ◽  
Color Change ◽  
Composite Resins ◽  
Control Group ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Tukey Test ◽  
Bleaching Gels ◽  
Bleaching Treatment

SUMMARY The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

scholarly journals Influence of chitosan coatings with citric essential oil on the shelf-life of minimally processed mango (Mangifera indica L.)

2015 ◽  
Vol 68 (2) ◽  
pp. 7679-7688
Author(s):  
Fabián Rico Rodríguez ◽  
Carolina Gutiérrez Cortés ◽  
Consuelo Díaz Moreno
Keyword(s):  
Weight Loss ◽  
Ascorbic Acid ◽  
Shelf Life ◽  
Mangifera Indica ◽  
The Other ◽  
Soluble Solids ◽  
Total Acidity ◽  
Minimally Processed ◽  
Color Changes ◽  
Sensory Acceptance

Demand for minimally processed fruits have increased due to their nutritional value and an increasing change in consumption habits. Physicochemical, microbiological, structural and sensory changes were determined in minimally processed mangoes (MPM) with chitosan (CH) edible coatings and lemon and orange essential oils (EOL). The MPM was first dipped in citric acid and a texturizing solution and then dipped in CH and lemon or orange EOL coatings. Weight loss, sensory acceptance, total soluble solids, total acidity, ascorbic acid, color changes, firmness and elasticity, and microbiological changes were quantified for 11 days of refrigerated storage. The CH and lemon EOL coating had more acceptance than the other treatments. No differences were found (p>0.05) for weight loss, total acidity, ascorbic acid, firmness or elasticity. There was a high amount of total phenols due to the EOL composition, as well as a high antioxidant capacity in the early days of storage. This characteristic decreased in the final days of the study. There was a decrease in the microbial charge for the lemon EOL treatment, as compared to the other samples. The CH and lemon EOL coating helped to maintain the shelf-life of the MPM for 11 days of storage without affecting the sensory acceptance. The CH and Orange EOL coating did not have an effect on the MPM physicochemical attributes; however, the sensory acceptance was negatively affected with off-flavors conferred to the MPM.

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