Assessment of Drying Protocol on the Bond Strength and Tag Penetration of Two Different Sealers to the Root Dentin: An In Vitro Study.

Accomplishment of an ideal root canal treatment is attributed to various essential factors such as proper instrumentation, chemomechanical preparation, obturation and post endodontic restoration. The main aim of this study is to test the null hypothesis that is the moisture condition of root dentin would not affect the bond strength and sealer penetration. This is an in vitro study conducted in Department of Conservative Dentistry and Endodontics, M A Rangoonwala Dental College, Pune, India over a period of two years (from 2021 to 2023). One hundred and twenty single-rooted Premolars with fully formed apices and similar root morphology were obtained and stored in 0.1% thymol solution. The specimens were randomly assigned to 3 broad experimental groups (n=40) according to the drying protocol such as Group A- Paper points (P), Group B- diode laser (L) and Group C- isopropyl alcohol (A). For each drying protocol, the specimens were further assigned to 2 subgroups (n=20) with respect to the sealers used: AH Plus (AH) and Apexit Plus sealers (APx). The effect of drying protocol using paper points, isopropyl alcohol and diode-lasers on the bond strength and tag penetration of two different sealers to the root dentin was evaluated. Maximum overall push-out Bond strength was seen in group AH+L and least in group APx+ L. Inter-site push-out bond Strength was highest in the coronal third followed by the middle and least in the apical third of all the groups. Maximum over all depth of penetration was seen in group AH+L and minimum in group APx+L. AH plus sealer showed better bond strength, sealer penetration and adaptation to the dentinal walls compared to Apexit plus sealer, irrespective of the drying protocol followed. All the drying protocols used did not show statistically significant results in the apical thirds of root canals of all the groups.

Optimal antiseptic skin preparation agents for minimizing surgical site infection following surgery: cost and cost-effectiveness analysis.

BACKGROUND: The application of antiseptic skin agents prior to incision minimizes the rate of surgical site infection. Despite their ubiquity, the optimal skin preparation agent remains uncertain. A retrospective economic analysis was conducted to complement the results from the NEWSkin Prep trial which prospectively compared three preparation agents. METHODS: A cost and cost-effectiveness analysis was performed from a healthcare service perspective to compare chlorhexidine with 70% ethanol, and aqueous povidone-iodine, against povidone-iodine with 70% ethanol. Resource use estimates accounted for hospital admissions, readmissions associated with surgical site infection, outpatient and general practitioner attendances, visits from community nurses and therapeutic consumables. The measure of effectiveness comprised the net difference in number of patients with surgical site infections per 1000 patients. Costs were compared using a two-sample Welch's t-test. Deterministic and probabilistic sensitivity analyses were performed to evaluate the incremental cost-effectiveness ratio. RESULTS: The null hypothesis that the mean costs for the trial arms were significantly different was not rejected (Welch's t-test P value: 0.771 for chlorhexidine with 70% ethanol against povidone-iodine with 70% ethanol; and 0.955 for aqueous povidone-iodine against povidone-iodine with 70% ethanol). Based on bootstrap averages, the chlorhexidine with 70% ethanol intervention generated 8.0 fewer surgical site infections per 1000 patients and net cost savings of €151,698 (Euros) per 1000 patients compared with povidone-iodine with 70% ethanol, and aqueous povidone-iodine produced a net cost saving of €37,494 per 1000 patients but generated an additional 11.6 surgical site infections per 1000 patients compared with povidone-iodine with 70% ethanol. The comparison of chlorhexidine with 70% ethanol to povidone-iodine with 70% ethanol was sensitive to the inclusion of cost outliers, while the comparison of aqueous povidone-iodine to povidone-iodine with 70% ethanol was sensitive to the estimated cost per surgical site infection. CONCLUSION: Based on the outcomes from the NEWSkin Prep study, this economic analysis found no definitive evidence in favour of any one of the study comparators. Future model-based economic analyses of alternative skin preparations should critically address the quality of evidence and integrate the results from the NEWSkin Prep study.

In vitro assessment of isopropanol leakage from antiseptic barrier caps into commonly used needleless connectors.

BACKGROUND: Needleless connectors (NCs) can be disinfected using antiseptic barrier caps (ABCs) to reduce the risk of catheter-related bloodstream infections. However, recent evidence suggests that isopropanol can leak from the ABC into the NC, posing concern about their safe use. We sought to determine in vitro which ABC and NC parameters influence the leakage of isopropanol through the infusion circuit. METHODS: We assessed 13 NCs and 4 ABCs available in the European market. In vitro circuits consisting of an isopropanol cap, a NC, and an 11-cm catheter line were created. The circuits were left in place for 1 to 7 days at room temperature to assess the kinetics of isopropanol leakage. Isopropanol content in ABC and in circuit flushing solutions (5 mL NaCl 0.9%) after exposure to the cap were measured using gas chromatography with a flame ionization detector. RESULTS: The leakage of isopropanol from the cap to the NC was dependent on the NC, but not the cap. The NC mechanism did not predict the leakage of isopropanol. The Q-Syte NC exhibited the most isopropanol leakage (7.01±1.03 mg and 28.32±2.62 mg at 24 hours and 7 days, respectively), whereas the Caresite NC had the lowest isopropanol leakage at 7 days (1.69±0.01 mg). CONCLUSION: The use of isopropanol ABCs can cause isopropanol leakage into the catheter circuit according to NC parameters. Caution should be exercised when using these devices, especially in the pediatric and neonatal population.

Low-Cost ZnO Spray-Coated Optical Fiber Sensor for Detecting VOC Biomarkers of Diabetes.

A non-invasive optical fiber sensor for detecting volatile organic compounds (VOCs) as biomarkers of diabetes is proposed and experimentally demonstrated. It offers a low-cost and straightforward fabrication approach by implementing a one-step spray coating of a ZnO colloidal solution on a glass optical fiber. The structure of the optical fiber sensor is based on a single-mode fiber-coreless silica fiber-single-mode fiber (SMF-CSF-SMF) structure, where the CSF is the sensor region spliced between two SMFs. The ZnO layer of a higher refractive index coated over the sensing region improves the light interaction with the surrounding medium, leading to sensitivity enhancement. The optical properties, morphology, and elemental composition of the ZnO layer were analyzed. The sensing mechanism of the developed sensor is based on a wavelength interrogation technique showing wavelength shifts when the sensor is exposed to various VOC vapor concentration levels. Various concentrations of the three VOCs (including acetone, isopropanol, and ethanol) ranging from 20% to 100% were tested and analyzed. The sensor noticeably shows a significant response towards acetone vapor, with a better sensitivity of 0.162 nm/% vapor than for isopropanol (0.082 nm/% vapor) and ethanol (0.075 nm/% vapor) vapors. The high sensitivity and selectivity towards acetone, a common biomarker for diabetes, offers the potential for further development of this sensor as a smart healthcare system for monitoring diabetic conditions.

Detecting Unique Analyte-Specific Radio Frequency Spectral Responses in Liquid Solutions-Implications for Non-Invasive Physiologic Monitoring.

With rising healthcare costs and the rapid increase in remote physiologic monitoring and care delivery, there is an increasing need for economical, accurate, and non-invasive continuous measures of blood analytes. Based on radio frequency identification (RFID), a novel electromagnetic technology (the Bio-RFID sensor) was developed to non-invasively penetrate inanimate surfaces, capture data from individual radio frequencies, and convert those data into physiologically meaningful information and insights. Here, we describe groundbreaking proof-of-principle studies using Bio-RFID to accurately measure various concentrations of analytes in deionized water. In particular, we tested the hypothesis that the Bio-RFID sensor is able to precisely and non-invasively measure and identify a variety of analytes in vitro. For this assessment, varying solutions of (1) water in isopropyl alcohol; (2) salt in water, and (3) commercial bleach in water were tested, using a randomized double-blind trial design, as proxies for biochemical solutions in general. The Bio-RFID technology was able to detect concentrations of 2000 parts per million (ppm), with evidence suggesting the ability to detect considerably smaller concentration differences.

Disinfection of Virtual Reality Devices in Health Care Settings: In Vitro Assessment and Survey Study.

BACKGROUND: Virtual reality (VR) devices are increasingly used in health care settings. The use among patients has the potential to unintentionally transmit pathogens between patients and hospital staff. No standard operating procedure for disinfection exists to ensure safe use between patients. OBJECTIVE: This study aims to determine the efficacy of disinfectants on VR devices in order to ensure safe use in health care settings. METHODS: Three types of bacteria were inoculated onto porous and nonporous surfaces of 2 VR devices: the Meta Oculus Quest and Meta Oculus Quest 2. Disinfection was performed using either isopropyl alcohol or alcohol-free quaternary ammonium wipes. A quantitative culture was used to assess the adequacy of disinfection. A survey was separately sent out to VR device technicians at other pediatric health care institutes to compare the methods of disinfection and how they were established. RESULTS: Both products achieved adequate disinfection of the treated surfaces; however, a greater log-kill was achieved on nonporous surfaces than on the porous surfaces. Alcohol performed better than quaternary ammonium on porous surfaces. The survey respondents reported a wide variability in disinfection processes with only 1 person reporting an established standard operating procedure. CONCLUSIONS: Disinfection can be achieved through the use of either isopropyl alcohol or quaternary ammonium products. Porous surfaces showed lesser log-kill rates than the nonporous surfaces, indicating that the use of an added barrier may be of benefit and should be a point of future research. Given the variability in the disinfection process across health care systems, a standard operating procedure is proposed.

Surgical solutions for preoperative skin preparation in total hip arthroplasty: A cost-effectiveness analysis of Betadine® and Chloraprep™.

OBJECTIVE: The purpose of our study was to compare the cost of surgical site skin preparation using ChloraPrep™ (2% chlorhexidine gluconate [CHG] and 70% isopropyl alcohol [IPA]) with skin cleansing using Betadine® Surgical Scrub and Betadine® 5% solution (povidone-iodine [PVI]) in total hip arthroplasty (THA). HYPOTHESIS: The hypothesis was that the ChloraPrep™ skin disinfection protocol reduces the cost of perioperative antisepsis. METHODS: A prospective database was created for all THAs performed at our university hospital between November 1st, 2020, and December 31st, 2020. Each surgeon was randomly assigned one type of antiseptic prior to the start of the study: one surgeon to the ChloraPrep™ group and one to the Betadine® group. In both groups, the enrollment stopped at the 15th patient. The costs related to consumables, waste disposal, and operating room occupancy time of each protocol were then assessed for each patient. RESULTS: The mean duration of the ChloraPrep™ protocol was 3.5±0.3minutes compared to 13.5±0.9minutes for the Betadine® protocol. The overall cost of a surgical site skin preparation involving all three steps was on average €46.8±4.2 for the ChloraPrep™ group compared to €155±10.9 for the Betadine® group (p<0.0001). DISCUSSION: Not only is the effectiveness of ChloraPrep™ already recognized but it also appears to have health economic benefits. However, further studies are needed to confirm this finding. LEVEL OF EVIDENCE: III, case control study.

Assessment of Successful qRT-PCR of SARS-CoV-2 Assay in Pool Screening Using Isopropyl Alcohol Purification Step in RNA Extraction.

The study is aimed at establishing the optimal parameters for RNA purification of pooled specimens, in SARS-CoV-2 assay. This research work evaluates the difference of extracted RNA purity of pooled samples with and without treatment with isopropyl alcohol and its effect on real-time RT-PCR. As per the protocol of the Indian Council of Medical Research (ICMR), 5 sample pools were analysed using qRT-PCR. A total of 100 pooled samples were selected for the study by mixing 50 µL of one COVID-19 positive nasopharyngeal/oropharyngeal (NP/OP) specimen and 50 µL each of 4 known negative specimens. Pool RNA was extracted using the column-based method, and 1 set of pooled extracted RNA was tested as such, while RNA of the second set was treated additionally with chilled isopropyl alcohol (modified protocol). Further, the purity of extracted RNA in both the groups was checked using Microvolume Spectrophotometers (Nanodrop) followed by RT-PCR targeting E-gene and RNaseP target. The results showed that the purity index of extracted RNA of untreated pooled specimens was inferior to isopropyl alcohol-treated templates, which was observed to be 85% sensitivity and 100% specificity. The average Cq (E gene) in the unpurified and purified pool RNA group was 34.66 and 31.48, respectively. The nanodrop data suggested that purified RNA concentration was significantly increased with an average value of 24.73 ± 1.49 ng/uL, which might be the reason for high sensitivity and specificity. Thus, this group testing of SARS-CoV-2 cases using pools of 5 individual samples would be the best alternative for saving molecular reagents, personnel time, and can increase the overall testing capacity. However, purity of RNA is one of the important determinants to procure unfailing results, thus, this additional purification step must be included in the protocol after RNA has been extracted using commercially available kit before performing qRT-PCR.

Assessment of occupational exposure to nebulized isopropyl alcohol as disinfectant during aseptic compounding of parenteral cytotoxic drugs in cleanrooms.

Pharmacy technicians are exposed to volatile organic compounds, like the disinfectant isopropyl alcohol (IPA), during the process of aseptic compounding of parenteral cytotoxic drugs. The occupational exposure to nebulized IPA during aseptic compounding has not been investigated. The aim of this study was to investigate the exposure to IPA during aseptic compounding of parenteral cytotoxic drugs and to assess compliance with legal and regulatory limits. As a secondary endpoint, the difference between two disinfection methods was compared regarding the exposure to IPA. The exposure to IPA was measured during five working shifts of 8 hr and one shift of 4 hr. The concentration IPA was measured by using a six-gas monitor. Total daily exposure was calculated as 8-hr Time Weighted Average (TWA) air concentration in mg/m3 and compared with an Occupational Exposure Limit (OEL) value of 500 mg/m3 and incidental peak exposure of 5,000 mg/m3. To assess whether the 8-hr TWA air concentration meets the legal and regulatory limits the Similar Exposure Groups (SEG) compliance test was used. A paired sample t-test was conducted to assess difference in exposure between two disinfection methods. The average 8-hr TWA exposure to IPA during the six measurements varied from 2.6 mg/m3 to 43.9 mg/m3 and the highest momentary concentration measured was 860 mg/m3. The result of the SEG compliance test was 3.392 (Ur value) and was greater than the Ut value of 2.187 which means the exposure to IPA is in compliance with the OEL value. No significant difference in exposure was shown between two disinfection methods (p = 0.49). In conclusion, exposure to IPA during aseptic compounding of parenteral cytotoxic drugs showed compliance to the OEL values with no significant difference in exposure between two disinfection methods.

Biochemical conversion of sugarcane bagasse into the alcohol fuel mixture of isopropanol-butanol-ethanol (IBE): Is it economically competitive with cellulosic ethanol?

This work presents a techno-economic analysis of the production of isopropanol, butanol, and ethanol (IBE) from sugarcane bagasse using clostridia and compares IBE with cellulosic ethanol for the minimum selling price (MSP) and sustainability aspects. The MSPs of the fuels are similar (15 USD/GJ) provided that glucose and xylose are effectively utilized in both processes, and the IBE process is equipped with a genetically-modified Clostridium species with enhanced IBE yield and a highly productive continuous bioreactor with integrated product recovery. Notably, these technologies can reduce the size (from 23 × 3785-m3 to 3 × 3027-m3 fermentation tanks) and the wastewater footprint (from 50 to 10 m3/m3 IBE) of the IBE plant. Furthermore, given that the production of either fuel results in a similar increase in the value created by the sugarcane biorefinery and its energy efficiency, the alcohol mixture produced by clostridia is a promising alternative to the less energy-dense ethanol fuel.

Comparative assessment of the effectiveness of three disinfection protocols for reducing bacterial contamination of stethoscopes.

In a crossover study, 30 stethoscopes were assessed and disinfected using 3 protocols: isopropyl alcohol, a quaternary ammonia or biguanide disinfectant, and ultraviolet germicidal irradiation (UVGI). All protocols effectively reduced bacterial loads, but UVGI was less effective at higher contamination levels (P = .0004). The effectiveness of each intervention was short in duration.

Cost-effectiveness analysis of chlorhexidine-alcohol versus povidone iodine-alcohol solution in the prevention of intravascular-catheter-related bloodstream infections in France.

OBJECTIVE: To perform a cost-effectiveness analysis of skin antiseptic solutions (chlorhexidine-alcohol (CHG) versus povidone iodine-alcohol solution (PVI)) for the prevention of intravascular-catheter-related bloodstream infections (CRBSI) in intensive care unit (ICU) in France based on an open-label, multicentre, randomised, controlled trial (CLEAN). DESIGN: A 100-day time semi-markovian model was performed to be fitted to longitudinal individual patient data from CLEAN database. This model includes eight health states and probabilistic sensitivity analyses on cost and effectiveness were performed. Costs of intensive care unit stay are based on a French multicentre study and the cost-effectiveness criterion is the cost per patient with catheter-related bloodstream infection avoided. PATIENTS: 2,349 patients (age≥18 years) were analyzed to compare the 1-time CHG group (CHG-T1, 588 patients), the 4-time CHG group (CHG-T4, 580 patients), the 1-time PVI group (PVI-T1, 587 patients), and the 4-time PVI group (PVI-T4, 594 patients). INTERVENTION: 2% chlorhexidine-70% isopropyl alcohol (chlorhexidine-alcohol) compared to 5% povidone iodine-69% ethanol (povidone iodine-alcohol). RESULTS: The mean cost per alive, discharged or dead patient was of €23,798 (95% confidence interval: €20,584; €34,331), €21,822 (€18,635; €29,701), €24,874 (€21,011; €31,678), and €24,201 (€20,507; €29,136) for CHG-T1, CHG-T4, PVI-T1, and PVI-T4, respectively. The mean number of patients with CRBSI per 1000 patients was of 3.49 (0.42; 12.57), 6.82 (1.86; 17.38), 26.04 (14.64; 42.58), and 23.05 (12.32; 39.09) for CHG-T1, CHG-T4, PVI-T1, and PVI-T4, respectively. In comparison to the 1-time PVI solution, the 1-time CHG solution avoids 22.55 CRBSI /1,000 patients, and saves €1,076 per patient. This saving is not statistically significant at a 0.05 level because of the overlap of 95% confidence intervals for mean costs per patient in each group. Conversely, the difference in effectiveness between the CHG-T1 solution and the PVI-T1 solution is statistically significant. CONCLUSIONS: The CHG-T1 solution is more effective at the same cost than the PVI-T1 solution. CHG-T1, CHG-T4 and PVI-T4 solutions are statistically comparable for cost and effectiveness. This study is based on the data from the RCT from 11 French intensive care units registered with www.clinicaltrials.gov (NCT01629550).

Results of a participatory needs assessment demonstrate an opportunity to involve people who use alcohol in drug user activism and harm reduction.

BACKGROUND: Drug users' organizations have made progress in recent years in advocating for the health and human rights of people who use illicit drugs but have historically not emphasized the needs of people who drink alcohol. METHODS: This paper reports on a qualitative participatory needs assessment with people who use illicit substances in British Columbia, Canada. We held workshops in 17 communities; these were facilitated by people who use illicit drugs, recorded with ethnographic fieldnotes, and analyzed using critical theory. RESULTS: Although the workshops were targeted to people who use illicit drugs, people who primarily consume alcohol also attended. An unexpected finding was the potential for drug users' organizations and other harm reduction programs to involve "illicit drinkers": people who drink non-beverage alcohol (e.g. mouthwash, rubbing alcohol) and those who drink beverage alcohol in criminalized ways (e.g., homeless drinkers). Potential points of alliance between these groups are common priorities (specifically, improving treatment by health professionals and the police, expanding housing options, and implementing harm reduction services), common values (reducing surveillance and improving accountability of services), and polysubstance use. CONCLUSIONS: Despite these potential points of alliance, there has historically been limited involvement of illicit drinkers in drug users' activism. Possible barriers to involvement of illicit drinkers in drug users' organizations include racism (as discourses around alcohol use are highly racialized), horizontal violence, the extreme marginalization of illicit drinkers, and knowledge gaps around harm reduction for alcohol. Understanding the commonalities between people who use drugs and people who use alcohol, as well as the potential barriers to alliance between them, may facilitate the greater involvement of illicit drinkers in drug users' organizations and harm reduction services.

Comparison of Antioxidant Capability after Isopropanol Salting-Out Pretreatment and n-Butanol Partition Extraction, and Identification and Evaluation of Antioxidants of Sedum formosanum N.E.Br.

Crude extracts of Sedum formosanum N.E.Br. obtained from n-butanol partition (BP) and isopropanol salting-out pretreatment (ISP) were analyzed using antioxidation assays. The results indicated that the extract from ISP contained more potent antioxidants and thus exhibited more antioxidant activity in all the assays. The superoxide radical-scavenging activity and inhibition of nitric oxide radicals achieved after ISP were 3.65 and 2.18 times higher than those achieved through BP, respectively. Eight bioactive natural products were isolated and identified according to an analysis of antioxidation activity in different fractions of the ISP crude extract, namely three cyanophoric glycosides 1-3, three flavonoids 4-6 and two phenolic compounds (7 and a new compound 8). Among them, compounds 5 and 6 exhibit the highest antioxidation capability, and the ISP is suitable for obtaining compounds 5 and 6 using HPLC chromatograms. Therefore, ISP is an excellent extraction technology that can be used to extract antioxidant compounds in the nutraceutical and pharmaceutical industries.

Quantitative assessment of methyl-esterification and other side reactions in a standard propionylation protocol for detection of histone modifications.

Histone modifications play an important role in regulating chromatin stability and gene expression, but to date, investigating them remains challenging. In order to obtain peptides suitable for MS-based analysis, chemical derivatization of N-terminus and lysine residues by propionic anhydride is commonly performed. Several side reactions (methyl-esterification, amidation, solvolysis, overpropionylation, and missed propionylation) during propionylation protocols have been described, yet their relative abundances remain vague. Because methyl-esterification could interfere with correct interpretation of the modification pattern, it is essential to take measures to avoid it. Here we present in-depth quantitative analyses of methyl-esterification and the other side reactions in a standard propionylation protocol containing methanol, and when replacing methanol with isopropanol or acetonitrile. We show that the use of alternative solvents can eliminate methyl-esterification and that even though other side reactions are not prevented, their contribution can be kept relatively small. We also show that replacing methanol can be of importance also in other proteomics methods, such as mixed cation exchange, using methanol under acidic conditions.

Performance analysis of exam gloves used for aseptic rodent surgery.

Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP-PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham 'exertion' activity. According to these criteria, 94% of HP-PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP-PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries.

Holographic assessment of self-phase modulation and blooming in a thermal medium.

The use of a low-power laser beam to characterize self-phase modulation (SPM) and bubble formation during thermal blooming (TB), as well as manipulation of the bubbles, is reported. First, a low-power 633 nm laser beam is used to characterize the induced refractive index profile during SPM of a focused 514 nm pump beam in absorbing liquid media, e.g., a solution of red dye in isopropyl alcohol. The induced phase change is also characterized using digital holography via the 633 nm source as the probe and reference. During TB at higher pump powers, bubble formation occurs in the liquid. Using a modified setup, which minimizes the effects of gravity, buoyancy, and convection, stable bubbles are generated. These are characterized using in-line digital holography with the 633 nm probe beam. It is shown that the bubble size depends on exposure time of the pump and that the bubble can be steered by moving a focused low-power laser beam. Finally, possible applications of these thermally generated bubbles are discussed.

Evaluation of semi-generic PBTK modeling for emergency risk assessment after acute inhalation exposure to volatile hazardous chemicals.

BACKGROUND: Physiologically Based Toxicokinetic Models (PBTK) may facilitate emergency risk assessment after chemical incidents with inhalation exposure, but they are rarely used due to their relative complexity and skill requirements. We aimed to tackle this problem by evaluating a semi-generic PBTK model built in MS Excel for nine chemicals that are widely-used and often released in a chemical incident. MATERIAL & METHODS: The semi-generic PBTK model was used to predict blood concentration-time curves using inhalation exposure scenarios from human volunteer studies, case reports and hypothetical exposures at Emergency Response Planning Guideline, Level 3 (ERPG-3) levels.(2) Predictions using this model were compared with measured blood concentrations from volunteer studies or case reports, as well as blood concentrations predicted by chemical-specific models. The performances of the semi-generic model were evaluated on biological rationale, accuracy, and ease of use and range of application. RESULTS: Our results indicate that the semi-generic model can be easily used to predict blood levels for eight out of nine parent chemicals (dichloromethane, benzene, xylene, styrene, toluene, isopropanol trichloroethylene and tetrachloroethylene). However, for methanol, 2-propanol and dichloromethane the semi-generic model could not cope with the endogenous production of methanol and of acetone (being a metabolite of 2-propanol) nor could it simulate the formation of HbCO, which is one of the toxic end-points of dichloromethane. The model is easy and intuitive to use by people who are not so familiar with toxicokinetic models. CONCLUSION: A semi-generic PBTK modeling approach can be used as a 'quick-and-dirty' method to get a crude estimate of the exposure dose.

Assessment of an innovative antimicrobial surface disinfectant in the operating room environment using adenosine triphosphate bioluminescence assay.

Terminal cleaning in the operating room is a critical step in preventing the transmission of health care-associated pathogens. The persistent disinfectant activity of a novel isopropyl alcohol/organofunctional silane solution (ISO) was evaluated in 4 operating rooms after terminal cleaning. Adenosine triphosphate bioluminescence documented a significant difference (P < .048) in surface bioburden on IOS-treated surfaces versus controls. RODAC plate cultures revealed a significant (P < .001) reduction in microbial contamination on IOS-treated surfaces compared with controls. Further studies are warranted to validate the persistent disinfectant activity of ISO within selective health care settings.