Neutralization of ricin toxin on building interior surfaces using liquid decontaminants.

Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant. Numerous recent incidents involving ricin have occurred, many in the form of mailed letters resulting in both building and mail sorting facility contamination. The goal of this study was to assess the decontamination efficacy of several commercial off-the-shelf (COTS) cleaners and decontaminants (solutions of sodium hypochlorite [bleach], quaternary ammonium, sodium percarbonate, peracetic acid, and hydrogen peroxide) against a crude preparation of ricin toxin. The ricin was inoculated onto four common building materials (pine wood, drywall joint tape, countertop laminate, and industrial carpet), and the decontaminants were applied to the test coupons using a handheld sprayer. Decontamination efficacy was quantified using an in-vitro cytotoxicity assay to measure the quantity of bioactive ricin toxin extracted from test coupons as compared to the corresponding positive controls (not sprayed with decontaminant). Results showed that decontamination efficacy varied by decontaminant and substrate material, and that efficacy generally improved as the number of spray applications or contact time increased. The solutions of 0.45% peracetic acid and the 20,000-parts per million (ppm) sodium hypochlorite provided the overall best decontamination efficacy. The 0.45% peracetic acid solution achieved 97.8 to 99.8% reduction with a 30-min contact time.

A geriatric game to strengthen older adult healthcare delivery and outcomes.

BACKGROUND: Serious games enhance learner engagement and knowledge, yet few medical education games target older adults' healthcare. Addressing this gap, we developed Geri-POP (Geriatrics Population Health), focusing on the Age-Friendly Health System (AFHS) framework and Geriatric 4Ms. METHODS: Geri-POP, a healthcare game is aimed at educating health profession learners about the AFHS framework. Geri-POP employs plan-do-study-act cycles of rapid improvement to apply AFHS principles and explore evidence-based geriatric practices within the game environment while garnering points for insight, trust and outcomes. Faculty and medical students were surveyed for feedback on an alpha version of Geri-POP. RESULTS: Players manage patient panels across three age groups (65-74, 75-84, and 85 years and older) while engaging in plan-do-study-act (PDSA) cycles, applying Geriatric 4Ms (What Matters, Medications, Mentation, and Mobility), and refining strategies based on resource utilization, health outcomes, and real-time feedback. Alpha testing of the game received mixed perceptions on graphics, with faculty endorsing the game for training and integration into the curriculum, while students prioritize academic commitments. Suggestions include enhancing graphics and refining dialogue for a more professional tone. CONCLUSIONS: Geri-POP demonstrates the potential of gamifying older adult population health and quality improvement around AFHS. Feedback on a prototype game revealed different attitudes between faculty and students, thus emphasizing the importance of game development as an iterative process that accounts for educator and learner-centric needs. A future consideration is whether the game informs user's clinical practices and changes healthcare outcomes for older adults.

Review of techniques for the in-situ sterilization of soil contaminated with Bacillus anthracis spores or other pathogens.

This review summarizes the literature on efficacy of techniques to sterilize soil. Soil may need to be sterilized if contaminated with pathogens such as Bacillus anthracis. Sterilizing soil in-situ minimizes spread of the bio-contaminant. Soil is difficult to sterilize, with efficacy generally diminishing with depth. Methyl bromide, formaldehyde, and glutaraldehyde are the only soil treatment options that have been demonstrated at full-scale to effectively inactivate Bacillus spores. Soil sterilization modalities with high efficacy at bench-scale include wet and dry heat, metam sodium, chlorine dioxide gas, and activated sodium persulfate. Simple oxidants such as chlorine bleach are ineffective in sterilizing soil.

Numerical Modeling of Toe-to-Heel Air Injection and Its Catalytic Variant (CAPRI) under Varying Steam Conditions.

There are huge reserves of heavy oil (HO) throughout the world that can be energy-intensive to recover. Improving the energy efficiency of the recovery process and developing novel methods of cleaner recovery will be essential for the transition from traditional fossil fuel usage to net-zero. In situ combustion (ISC) is a less used technique, with toe-to-heel air injection (THAI) and catalytic processing in situ (CAPRI) being specialized novel versions of traditional ISC. They utilize a horizontal producing well and in the case of CAPRI, a catalyst. This paper aims to investigate the impact that injected steam has on both the THAI and CAPRI processes for the purpose of in situ HO upgrading and will help to bridge the gap between the extant laboratory research and the unknown commercial potential. This study also presents a novel method for modeling the THAI-CAPRI method using CMG STARS, proposing an in situ hydrogen production reaction scheme. THAI and CAPRI experimental-scale models were run under three conditions: dry, pre-steam, and constant steam. Starting from a reservoir American Petroleum Institute (API) of 10.5°, THAI reached an average API of ∼16 points, showing no increase in the API output with the use of steam injection. A decreased API output by ∼0.7 points during constant steam injection was achieved due to a high-temperature oxidation-dominant environment. This decreases the reactant availability for thermal cracking. The CAPRI dry run reached an API of 20.40 points and achieved an increased API output for both pre-steaming (∼21.17 points) and constant steaming (∼22.13 points). The mechanics for this increased upgrading were discussed, and catalytic upgrading, as opposed to thermal cracking, was shown to be the reason for the increased upgrading. Both processes produce similar cumulative oil (∼3150 cm3) during dry and pre-steamed runs, only increasing to ∼3300 cm3 with the constant steam injection during THAI and 3500 cm3 for CAPRI.

Effectiveness of formaldehyde in various soil types as a wide area decontamination approach for Bacillus anthracis spores.

The purpose of this study was to evaluate and compare the decontamination efficacy of liquid formaldehyde solutions for three soil types (sand, loam, and clay) against spores of Bacillus anthracis (B.a.) and Bacillus atrophaeus. Approximately 1 x 108 colony forming units were inoculated into each sample. Through a series of six bench-scale experiments, two concentrations and two volumes of liquid formaldehyde solution were then added to the soil samples and allowed to remain in contact for either 24 or 48 hours. Decontamination efficacy was assessed at either 22° or 10°C with or without lids atop the sample jars. Complete inactivation (no spores recovered from the soil samples, typically providing > 7 log reduction) of B.a. occurred in all soil types in five of the six tests, while complete inactivation of B. atrophaeus was achieved in all soil types for three of the six tests. The results demonstrated a higher probability of complete inactivation of spores for samples that were covered, samples that received the higher volume of formaldehyde, and those contaminated with B.a. Overall, the use of liquid formaldehyde solution (2.5-5%) was highly effective in inactivating entire spore populations (typically > 107 CFU) for both B.a. and B. atrophaeus in the soil matrices studied. Covering the soil after application would allow for less formaldehyde solution to be used without impacting the overall efficacy of the process. The data from this study may aid in the selection of appropriate decontamination parameters when using liquid formaldehyde for soil remediation. The data may also aid in the decision to use B. atrophaeus as a surrogate for B.a. when performing further decontamination studies using liquid formalin solutions.

Decontamination efficacy of common liquid disinfectants against non-spore-forming biological agents in soil matrices.

AIMS: The purpose of this study was to evaluate decontamination efficacy, within three soil types, against Yersinia pestis, Burkholderia pseudomallei, and the Venezuelan Equine Encephalitis virus (VEEV). METHODS AND RESULTS: One of three liquid disinfectants (dilute bleach, Virkon-S or Klozur One) was added to three soil types (sand, loam, or clay) and allowed contact for four pre-spike durations: 0, 15, 30 and 60 min. Y. pestis, B. pseudomallei, or VEEV was then spiked into the soil (10 microliters or approx. 1 × 107  CFU or PFU into 1 g soil) and decontamination efficacy assessed at post-spike contact times of 10 or 60 min at ambient environmental conditions. Across all soil types, sandy soil resulted in the least quenching to all three disinfectants tested as shown by sustained decontamination efficacy across all pre-spike and post-spike timepoints. Clay and loam soil types exhibited quenching effects on the hypochlorite and peroxygen based disinfectants (dilute bleach and Virkon S) and in general resulted in decreased efficacy with increased pre-spike contact time. The sodium persulfate (Klozur One) performance was the most consistent across all soil types and pre-spike contact times, resulting in greater efficacy with increased post-spike time. CONCLUSIONS: Liquid disinfectants can provide high levels of decontamination in soil for both viral and non-spore-forming bacterial select agents. Hypochlorite and peroxygen based disinfectants used in soils containing higher organic content (loam or clay) may require extended contact times or re-application of liquid disinfectant, in as little as 15 min of application, to achieve a 6-log reduction. SIGNIFICANCE AND IMPACT OF THE STUDY: These results provide information for the performance of three disinfectants in soil against non-spore-forming select agents. These data may aid response decision makers following a biological contamination incident by informing the selection of disinfectant as well as the re-application time to achieve effective site remediation.

Methanolysis of Poly(lactic Acid) Using Catalyst Mixtures and the Kinetics of Methyl Lactate Production.

Polylactic acid (PLA) is a leading bioplastic of which the market share is predicted to increase in the future; its growing production capacity means its end-of-life treatment is becoming increasingly important. One beneficial disposal route for PLA is its chemical recycling via alcoholysis. The alcoholysis of PLA leads to the generation of value-added products alkyl lactates; this route also has potential for a circular economy. In this work, PLA was chemically recycled via methanolysis to generate methyl lactate (MeLa). Four commercially available catalysts were investigated: zinc acetate dihydrate (Zn(OAc)2), magnesium acetate tetrahydrate (Mg(OAc)2), 4-(dimethylamino)pyridine (DMAP), and triazabicyclodecene (TBD). Dual catalyst experiments displayed an increase in reactivity when Zn(OAc)2 was paired with TBD or DMAP, or when Mg(OAc)2 was paired with TBD. Zn(OAc)2 coupled with TBD displayed the greatest reactivity. Out of the single catalyst reactions, Zn(OAc)2 exhibited the highest activity: a higher mol% was found to increase reaction rate but plateaued at 4 mol%, and a higher equivalent of methanol was found to increase the reaction rate, but plateaued at 17 equivalents. PLA methanolysis was modelled as a two-step reversible reaction; the activation energies were estimated at: Ea1 = 25.23 kJ∙mol-1, Ea2 = 34.16 kJ∙mol-1 and Ea-2 = 47.93 kJ∙mol-1.

Evaluation of electrostatic sprayers and foggers for the application of disinfectants in the era of SARS-CoV-2.

Although research has shown that the COVID-19 disease is most likely caused by airborne transmission of the SARS-CoV-2 virus, disinfection of potentially contaminated surfaces is also recommended to limit the spread of the disease. Use of electrostatic sprayers (ESS) and foggers to rapidly apply disinfectants over large areas or to complex surfaces has emerged with the COVID-19 pandemic. ESSs are designed to impart an electrostatic charge to the spray droplets with the goal of increasing deposition of the droplets onto surfaces, thereby promoting more efficient use of the disinfectant. The purpose of this research was to evaluate several spray parameters for different types of sprayers and foggers, as they relate to the application of disinfectants. Some of the parameters evaluated included the spray droplet size distribution, the electrostatic charge, the ability of the spray to wrap around objects, and the loss of disinfectant chemical active ingredient due to the spray process. The results show that most of the devices evaluated for droplet size distribution had an average volume median diameter ≥ 40 microns, and that four out of the six ESS tested for charge/mass produced sprays of at least 0.1 mC/kg. A minimal wrap-around effect of the spray deposition onto a cylindrical object was observed. The loss of disinfectant active ingredient to the air due to spraying was minimal for the two disinfectants tested, and concurrently, the active ingredient concentrations of the liquid disinfectants sprayed and collected 3 feet (1 meter) away from the spray nozzle do not decrease.

Comparative Study on the Hydrogenation of Naphthalene over Both Al2O3-Supported Pd and NiMo Catalysts against a Novel LDH-Derived Ni-MMO-Supported Mo Catalyst.

Naphthalene hydrogenation was studied over a novel Ni-Al-layered double hydroxide-derived Mo-doped mixed metal oxide (Mo-MMO), contrasted against bifunctional NiMo/Al2O3, and Pd-doped Al2O3 catalysts, the latter of which with Pd loadings of 1, 2, and 5 wt %. Reaction rate constants were derived from a pseudo-first-order kinetic pathway describing a two-step hydrogenation pathway to tetralin (k 1) and decalin (k 2). The Mo-MMO catalyst achieved comparable reaction rates to Pd2%/Al2O3 at double concentration. When using Pd5%/Al2O3, tetralin hydrogenation was favored over naphthalene hydrogenation culminating in a k 2 value of 0.224 compared to a k 1 value of 0.069. Ni- and Mo-based catalysts produced the most significant cis-decalin production, with Mo-MMO culminating at a cis/trans ratio of 0.62 as well as providing enhanced activity in naphthalene hydrogenation compared to NiMo/Al2O3. Consequently, Mo-MMO presents an opportunity to generate more alkyl naphthenes in subsequent hydrodecyclization reactions and therefore a higher cetane number in transport fuels. This is contrasted by a preferential production of trans-decalin observed when using all of the Al2O3-supported Pd catalysts, as a result of octalin intermediate orientations on the catalyst surface as a function of the electronic properties of Pd catalysts.

Psychometric properties of the Cambridge-Mindreading Face-Voice Battery for Children in children with ASD.

This study examined the psychometric characteristics of the Cambridge-Mindreading Face-Voice Battery for Children (CAM-C) for a sample of 333 children, ages 6-12 years with ASD (with no intellectual disability). Internal consistency was very good for the Total score (0.81 for both Faces and Voices) and respectable for the Complex emotions score (0.72 for Faces and 0.74 for Voices); however, internal consistency was lower for Simple emotions (0.65 for Faces and 0.61 for Voices). Test-retest reliability at 18 and 36 weeks was very good for the faces and voices total (0.76-0.81) and good for simple and complex faces and voices (0.53-0.75). Significant correlations were found between CAM-C Faces and scores on another measure of face-emotion recognition (Diagnostic Analysis of Nonverbal Accuracy-Second Edition), and between Faces and Voices scores and child age, IQ (except perceptual IQ and Simple Voice emotions), and language ability. Parent-reported ASD symptom severity and the Emotion Recognition scale on the SRS-2 were not related to CAM-C scores. Suggestions for future studies and further development of the CAM-C are provided. LAY SUMMARY: Facial and vocal emotion recognition are important for social interaction and have been identified as a challenge for individuals with autism spectrum disorder. Emotion recognition is an area frequently targeted by interventions. This study evaluated a measure of emotion recognition (the CAM-C) for its consistency and validity in a large sample of children with autism. The study found the CAM-C showed many strengths needed to accurately measure the change in emotion recognition during intervention.

Formaldehyde Vapor Characteristics in Varied Decontamination Environments.

INTRODUCTION: This effort investigated formaldehyde vapor characteristics under various environmental conditions by the analyses of air samples collected over a time-course. This knowledge will help responders achieve desired formaldehyde exposure parameters for decontamination of affected spaces after a biological contamination incident. METHODS: Prescribed masses of paraformaldehyde and formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor. Adsorbent cartridges were used to collect air samples from the test chamber at predetermined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. In addition, material demand for the formaldehyde was evaluated by inclusion of arrays of Plexiglas panels in the test chamber to determine the impact of varied surface areas within the test chamber. Temperature was controlled with a circulating water bath connected to a radiator and fan inside the chamber. Relative humidity was controlled with humidity fixed-point salt solutions and water vapor generated from evaporated water. RESULTS: Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations in the ambient temperature trials (approximately 22°C). The addition of clear Plexiglas panels to increase the surface area of the test chamber interior resulted in appreciable decreases of formaldehyde air concentration when compared to an empty test chamber. CONCLUSION: This work has shown that environmental variables and surface-to-volume ratios in the decontaminated space may affect the availability of formaldehyde in the air and, therefore, may affect decontamination effectiveness.

Decontamination of Bacillus Spores with Formaldehyde Vapor under Varied Environmental Conditions.

Introduction: This study investigated formaldehyde decontamination efficacy against dried Bacillus spores on porous and non-porous test surfaces, under various environmental conditions. This knowledge will help responders determine effective formaldehyde exposure parameters to decontaminate affected spaces following a biological agent release. Methods: Prescribed masses of paraformaldehyde or formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor within a bench-scale test chamber. Adsorbent cartridges were used to measure formaldehyde vapor concentrations in the chamber at pre-determined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. Spores of Bacillus globigii, Bacillus thuringiensis, and Bacillus anthracis were inoculated and dried onto porous bare pine wood and non-porous painted concrete material coupons. A series of tests was conducted where temperature, relative humidity, and formaldehyde concentration were varied, to determine treatment efficacy outside of conditions where this decontaminant is well-characterized (laboratory temperature and humidity and 12 mg/L theoretical formaldehyde vapor concentration) to predict decontamination efficacy in applications that may arise following a biological incident. Results: Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations collected in the ambient temperature trials (approximately 22°C). Generally, decontamination efficacy on wood was lower for all three spore types compared with painted concrete. Also, higher recoveries resulted from painted concrete compared to wood, consistent with historical data on these materials. The highest decontamination efficacies were observed on the spores subjected to the longest exposures (48 hours) on both materials, with efficacies that gradually decreased with shorter exposures. Adsorption or absorption of the formaldehyde vapor may have been a factor, especially during the low temperature trials, resulting in less available formaldehyde in the air when measured. Conclusion: Environmental conditions affect formaldehyde concentrations in the air and thereby affect decontamination efficacy. Efficacy is also impacted by the material with which the contaminants are in contact.

In-situ microwave-assisted catalytic upgrading of heavy oil: Experimental validation and effect of catalyst pore structure on activity.

In-situ combustion alone may not provide sufficient heating for downhole, catalytic upgrading of heavy oil in the Toe-to-Heel Air Injection (THAI) process. In this study, a new microwave heating technique has been proposed as a strategy to provide the requisite heating. Microwave technology is alone able to provide rapid heating which can be targeted at the catalyst packing and/or the incoming oil in its immediate vicinity. It was demonstrated, contrary to previous assertions, that heavy oil can be heated directly with microwaves to 425 °C, which is the temperature needed for successful catalytic upgrading, without the need for an additional microwave susceptor. Upgrading of >3.2° API points, a reduction in viscosity to less than 100 cP, and >12% reduction in sulfur content was achieved using commercially available hydrodesulfurization (HDS) catalyst. The HDS catalyst induced dehydrogenation, with nearly 20% hydrogen detected in the gas product. Hence, in THAI field settings, part of the oil-in-place could be sacrificed for dehydrogenation, with the produced hydrogen directed to aid hydrodesulfurization and improve upgrading. Further, this could provide a route for downhole hydrogen production, which can contribute to the efforts towards the hydrogen economy. A single, unified model of evolving catalyst structure was developed. The model incorporated the unusual gas sorption data, computerized x-ray tomography and electron microprobe characterization, as well as the reaction behavior. The proposed model also highlighted the significant impact of the particular catalyst fabrication process on the catalytic activity.

Decontamination of soil contaminated at the surface with Bacillus anthracis spores using dry thermal treatment.

In the event of a large, aerosol release of Bacillus anthracis spores in a major metropolitan area, soils and other outdoor materials may become contaminated with the biological agent. A study was conducted to assess the in-situ remediation of soil using a dry thermal treatment approach to inactivate a B. anthracis spore surrogate inoculated into soil samples. The study was conducted in two phases, using loam, clay and sand-based soils, as well as biological indicators and spore-inoculated stainless-steel coupons. Initial experiments were performed in an environmental test chamber with temperatures controlled between 80 and 110 °C, with and without added humidity, and with contact times ranging from 4 h to 7 weeks. Tests were then scaled up to assess the thermal inactivation of spores in small soil columns, in which a heating plate set to 141 °C was applied to the soil surface. These column tests were conducted to assess time requirements to inactivate spores as a function of soil depth and soil type. Results from the initial phase of testing showed that increasing the temperature and relative humidity reduced the time requirements to achieve samples in which no surrogate spores were detected. For the test at 80 °C with no added humidity, 49 days were required to achieve soil samples with no spores detected in clay and loam. At 110 °C, 24 h were required to achieve samples in which no spores were detected. In the column tests, no spores were detected at the 2.5 cm depth at four days and at the 5.1 cm depth at 21 days, for two of the three soils. The experiments described in the study demonstrate the feasibility of using dry thermal techniques to decontaminate soils that have been surficially contaminated with B. anthracis spores.

Chemical Degradation of End-of-Life Poly(lactic acid) into Methyl Lactate by a Zn(II) Complex.

The catalyzed methanolysis of end-of-life poly(lactic acid) (PLA) products by an ethylenediamine Zn(II) complex to form biodegradable methyl lactate was studied experimentally at 70, 90, and 110 °C. The PLA samples consisted of typical consumer waste materials, including a cup, a toy, and a three-dimensional (3D) printing material. High selectivities and yields (>94%) were possible depending on temperature and reaction time. Additionally, and to develop a predictive kinetic model, kinetic parameters (pre-exponential factor and activation energies) of the PLA transesterification reaction were first obtained from virgin PLA. These parameters were subsequently used to estimate the conversion of PLA, selectivity, and yield of methyl lactate after 1 and 4 h of the reaction, and the results were compared with the experimental values of the end-of-life PLA. Despite the presence of unknown additives in the PLA waste material and uncontrolled particle size, the model was able to predict the overall conversion, selectivity, and yield to an average deviation of 5, 7, and 12%, respectively. A greater agreement between the model and experimental values is observed for the higher temperatures and the longer reaction time. Larger deviations were observed for the PLA toy, which we attribute to the presence of additives, since despite its lower molecular weight, it possessed a higher structural strength.

The use of ozone gas for the inactivation of Bacillus anthracis and Bacillus subtilis spores on building materials.

A study was conducted to assess the efficacy of ozone gas in inactivating spores of both Bacillus anthracis and Bacillus subtilis inoculated onto six building materials (glass, wood, carpet, laminate, galvanized metal, and wallboard paper). Testing conditions consisted of ozone gas concentrations ranging from 7,000-12,000 parts per million (ppm), contact times from 4 to 12 h, and two relative humidity (RH) levels of 75 and 85%. Results showed that increasing the ozone concentration, contact time, and RH generally increased decontamination efficacy. The materials in which the highest decontamination efficacy was achieved for B. anthracis spores were wallboard paper, carpet, and wood with ≥ 6 log10 reduction (LR) occurring with 9,800 ppm ozone, 85% RH, for 6 h. The laminate and galvanized metal materials were generally more difficult to decontaminate, requiring 12,000 ppm ozone, 85% RH, and 9-12 h contact time to achieve ≥6 LR of B. anthracis. Lastly, overall, there were no significant differences in decontamination efficacy between the two species.

Kinetics of Methyl Lactate Formation from the Transesterification of Polylactic Acid Catalyzed by Zn(II) Complexes.

The kinetics of the transesterification of polylactic acid (PLA) with methanol to form methyl lactate catalyzed by Zn(II) complexes was studied experimentally and numerically. The complexes, Zn(1 Et )2 and Zn(2 Pr )2, were synthesized from ethylenediamine and propylenediamine Schiff bases, respectively. The temperature range covered was 313.2-383.2 K. An increase in the reaction rate with the increase in temperature was observed for the Zn(1 Et )2-catalyzed reaction. The temperature relationship of the rate coefficients can be explained by a linear Arrhenius dependency with constant activation energy. The kinetics of Zn(2 Pr )2, on the other hand, is only explained by non-Arrhenius kinetics with convex variable activation energy, resulting in faster methyl lactate production rates at 323.2 and 343.2 K. The formation of a new catalyst species, likely through reaction with protic reagents, appears to promote the formation of intermediate complexes, resulting in the nonlinear behavior. Stirring speed induced the stability of the intermediate complexes. Contrary to Zn(1 Et )2, Zn(2 Pr )2 was susceptible to the presence of air/moisture in solution. The kinetic parameters were obtained by fitting the experimental data to the mass and energy balance of a consecutive second step reversible reaction taking place in a jacketed stirred batch reactor. For the case of Zn(2 Pr )2, the activation energy was fitted to a four-parameter equation. The kinetic parameters presented in this work are valuable for the design of processes involving the chemical recycling of PLA into green solvents.

Evaluating the Environmental Persistence and Inactivation of MS2 Bacteriophage and the Presumed Ebola Virus Surrogate Phi6 Using Low Concentration Hydrogen Peroxide Vapor.

Ebola virus (EBOV) disease outbreaks, as well as the ability of EBOV to persist in the environment under certain conditions, highlight the need to develop effective decontamination techniques against the virus. We evaluated the efficacy of hydrogen peroxide vapor (HPV) to inactivate MS2 and Phi6 bacteriophages, the latter a recommended surrogate for EBOV. The phages were inoculated onto six material types with and without the presence of whole human blood. The inoculated materials were then exposed to either a high or low concentration of HPV for various elapsed times. The phages were also recovered from positive controls at these same elapsed times, to assess environmental persistence and decontamination efficacy. Low concentration hydrogen peroxide vapor (LCHP; 25 ppm) was effective against both phages on all materials without the presence of blood at 2 h. LCHP was ineffective against the phages in the presence of blood, on all materials, even with a 3-day contact time. Higher concentrations of HPV (>400 ppm) with contact times of 24-32 h achieved approximately 2-6 log reduction of the phages in the presence of blood.

Craniotomy for recurrent glioblastoma: Is it justified? A comparative cohort study with outcomes over 10 years.

OBJECTIVE: The role of repeat resection for recurrent glioblastoma multiforme (rGBM) is unclear. This large comparative cohort study assessed overall survival (OS), survival since recurrence (SSR), quality of life, and complications in reoperated versus non-reoperated patients for rGBM. PATIENTS AND METHODS: All patients with rGBM between 2005 and 2015, who were discussed by our institution's multi-disciplinary team, and who either did or did not undergo reoperation, were prospectively followed up with data collected and compared. Survival and prognostic factors were analysed using Kaplan-Meier and Cox regression methods. RESULTS: 312 patients (reoperated, n = 145; non-reoperated, n = 167) were analysed. Median SSR was 10.8 months and 6.9 months in the reoperated and non-reoperated groups respectively (Log-rank test: p = 0.02). Median OS was 24.1 months and 20.4 months in the reoperated and non-reoperated groups, respectively (Log-rank test: p = 0.04). Quality of life as measured by Short Form 36 scores were 59 versus 54 at baseline and 62 versus 51 at four-month follow-up for re-operated and non-reoperated groups, respectively (p < 0.05). Age < 60 years, Karnofsky Performance Status (KPS) ≥ 80, recurrence ≥ 9 months from initial diagnosis, methylguanine methyltransferase (MGMT) promoter methylation, and extent of resection (EOR) > 80 %, each were significant predictors of SSR and OS. Complication rates were 5.5 % and 6.2 % following repeat resection and primary resection, respectively (p > 0.05). CONCLUSION: This is the first large prospective comparative cohort study of rGBM and demonstrates that repeat resection confers a small but significant benefit in survival and quality of life over non-operative treatment. Best prognosis is associated with: younger age, KPS ≥ 80, late recurrence, MGMT promoter methylation and EOR > 80 %.