Residual Contamination Levels Research Articles

Forecast of Foreground Cleaning Strategies for AliCPT-1

We report the test results of several independent foreground cleaning pipelines used in the Ali CMB Polarization Telescope experiment (AliCPT-1), a high-altitude cosmic microwave background (CMB) imager in the Northern Hemisphere with thousands of detectors dedicated to the search for a primordial CMB polarization B-mode signature. Based on simulated data from four detector modules and a single season of observation, which we refer to as Data Challenge 1 (DC1), we employ different and independent pipelines to examine the robustness and effectiveness of estimates on foreground parameters and primordial B-mode detection. The foreground cleaning strategies used in the pipelines include the parametric method of template fitting (TF) and the nonparametric methods of constrained internal linear combination (cILC), analytical blind separation (ABS), and generalized least squares (GLS). We examine the impact of possible foreground residuals on the estimate of the CMB tensor-to-scalar ratio (r) for each pipeline by changing the contamination components in the simulated maps and varying the foreground models and sky patches for various tests. According to the DC1 data with the simulation input value r true = 0.023, the foreground residual contamination levels in the TF/ABS/cILC/GLS pipelines are well within the corresponding statistical errors at the 2σ level. Furthermore, by utilizing the tension estimator, which helps identify significant residual foreground contamination in the detection of the primordial B-mode signal by quantifying the discrepancy between various r measurements, we conclude that the presence of small foreground residuals does not lead to any significant inconsistency in the estimation of r.

СТАБИЛИЗАЦИЯ ПРОЦЕССА – УСЛОВИЕ ЕГО ОБЪЕКТИВНОГО ИССЛЕДОВАНИЯ

Research of the interrelationships between the time periods of stabilization of the technological process of trier grain cleaning from: feeding the grain mixture into the trier; its initial contamination; speed mode of operation and angular position of the output tray relative to the horizon are satisfied. They were carried out using experimental equipment that provided separate, regulated and continuous supply of grain mixture components into the trier with a looped movement of purified grain. Standard methods and instruments, as well as special instruments developed at the Federal State Budgetary Institution VNIITiN, were used to assess the physical and mechanical properties of the components of the grain mixture. It was found that with a supply of 1.2 t/h, an initial contamination of 1.3% and a lifting angle of the output tray of 55°, the speed mode of operation of 36.0 rpm is excessive, while stabilization of the process is not completed even after 15 minutes (92% ), the length of the free section of the cellular surface is 0.70 - 0.75 m, which increases the level of residual grain contamination to 0.025 - 0.04%, which does not meet the requirements for seeds of the OS category. The possibility of reducing the comparable level of process stabilization by 6 times when the operating speed is reduced to 34.6 rpm (by 3.9%) has been confirmed. Reducing the operating speed to 34.0 rpm leads to an increase in process losses to 16.85%. It has been established that with an increase in the initial contamination of the grain mixture to 2.6%, the stabilization period of the process at a speed mode of 34.6 rpm increases from 4.5 to 5.5 minutes, and technological losses reach the maximum permissible value (5%). The method for calculating the actual degree of stabilization of the process with its assessment based on the removal of impurities has been refined.

Assessing decontamination practices at a medical microbiology research laboratory

To our knowledge, this is the first study to conduct an objective assessment of the routine decontamination practices at a medical microbiology research laboratory (MRL) a year after a biosafety training was provided to all laboratory staff. Between March 28th and June 28th, 2021, unobtrusive observations were carried out to identify-three high-touch surfaces at the MRL during different working hours. Swabbing was used to evaluate the effectiveness of the disinfectant used in the laboratory. All three high-touch surfaces were sampled before and after decontamination with 200 ppm of 5 % sodium hypochlorite (household bleach) to quantify the microbial load and identify the types of organisms residing on the laboratory surfaces. A higher concentration (500 ppm) of 5 % sodium hypochlorite was employed after refresher training was provided to housekeeping staff, and resampling of the three surfaces was carried out during a 4-week follow-up period using the same procedure. The three high-touch surfaces identified were the two sides of the workbench (22 %–24 %) and the front surface of one incubator (14 %). Anthracoid bacilli and Staphylococcus aureus were the most commonly found organisms on laboratory surfaces pre-intervention (100 % and 89 %, respectively) and post-intervention (56 % and 44 %, respectively). Other microorganisms detected included Salmonella spp. (27.7 %), Proteus spp. (5.6 %), Escherichia coli (5.6 %), and Klebsiella spp. (33.3 %). Employing a higher concentration (500 ppm) of sodium hypochlorite significantly (p ≤ 0.000) reduced the total aerobic colony count from an average of 15–250 cfu/cm2 to 10–60 cfu/cm2. This study demonstrated suboptimal decontamination practices at the MRL and the need to apply a higher concentration (500 ppm) of sodium hypochlorite to reduce the overall microbial load. It also demonstrated the importance of quantitative assessment to monitor decontamination practices and ensure staff compliance. More studies are needed to identify bacterial communities within the laboratory, which will help provide guidance regarding the types, proper concentrations, and appropriateness of the in -use disinfectants. Furthermore, large-scale studies on the acceptable level of residual contamination following any decontamination process are urgently recommended.

СПОСОБ ОПРЕДЕЛЕНИЯ ОПТИМАЛЬНОЙ ДЛИНЫ ТРИЕРНОГО ЦИЛИНДРА

. It is known that agricultural enterprises are equipped with grain cleaning units of the ZAV40 and KZS-40 types. It is known that in 90% of cases trier blocks of units are taken out of service, since they do not provide the required quality of grain cleaning and are unreliable in operation - technological failures occur due to blockages of cellular cylinders. This problem can be partially solved by using indented blocks with the optimal length of the indented cylinder. This will lead to a significant reduction in the loss of clean grain to waste while maintaining an acceptable level of residual contamination and increasing reliability. A mathematical model has been developed for the operation of the grading unit according to the parameters of residual contamination and losses of clean grain. It was found that the residual contamination decreases exponentially along the length of the doll cylinder. The loss of clean grain to waste grows linearly. It was found that the loss of pure grain to waste along the length of the oat cylinder decreases exponentially. A formula has been obtained to determine the optimal length of the indented cylinder, which depends on the degree of impurity release and the amount of pure grain loss for the doll cylinder. The criterion of optimal operation of the indenter block has been substantiated. The hypothesis about the same degree of impurity release along the entire length of the indented cylinder was confirmed. On the basis of the results obtained, recommendations are given for the developers of indented blocks.

Real-time detection of Chemical Warfare Agents at clearance decontamination levels for surface contamination: a challenge for civilian authorities

NATO doctrine considers clearance decontamination to be applicable after the termination of a CBRN incident and largely deems the conduct of clearance decontamination to be a civilian, not a military, capability (NATO Standard NATO STANREC 4784 CBRN Clearance Decontamination, Study Draft 1, November 2015). Clearance decontamination procedures are such that the process is verified as being achieved by determining the residual contamination levels on every part of various surfaces of equipment and infrastructure, and by demonstrating that such levels are below the ones that are pre-determined by the relevant civilian authorities, who are responsible for the safety of the civilian population (NATO Standard NATO STANREC 4784 CBRN Clearance Decontamination, Study Draft 1, November 2015). The current desirable surface contamination detection levels for some Chemical Warfare Agents are technically challenging and may be beyond the capabilities of current technologies of military and civilian authorities. Can those low levels be detected, in real time, with existing technologies? Proton Transfer Reaction–Time of Flight–Mass Spectrometry (PTR–ToF–MS) enables simultaneous real-time detection, monitoring, and quantification of volatile organic compounds. Trials and evaluations with this PTR–ToF–MS technology, using Chemical Warfare Agents as contaminants, will show that this technology is an invaluable asset in supporting civilian authorities when determining safe levels of surface contamination in real time, after the completion of decontamination operations.

Регенерация металлических радиоактивных отходов радиохимических производств для целей повторного использования металлов и сплавов

The paper proposes a processing method for metal radioactive waste (high alloyed stainless steel and its alloys) containing transuranic radionuclides. This type of waste is generated during operation and decommissioning of SNF reprocessing equipment at radiochemical production facilities. To ensure the recycling of valuable components, decontamination and conditioning of the regenerated ingots to high-quality metal is arranged in a two-staged process involving MRW remelting: its first stage involves in-depth metal decontamination under a layer of a refining flux, whereas the second stage provides for additional metal treatment to remove radioactive and stable impurities, as well as metal alloying to make up for the "burnt out" valuable components and to level its chemical composition. The process is implemented at an enterprise specialized in RW processing having appropriate infrastructure facilities and licenses authorizing relevant operations with radioactive materials. Metal radioactive waste regeneration results in a grade metal, which in terms of its residual radioactive contamination level can be released from radiation control and admitted to unrestricted use. It has been experimentally demonstrated that ESR, when used for MRW decontamination purposes, allows to obtain high-quality steel suitable for future reuse.

Effectiveness of a decontamination procedure in a pharmacy buffer room contaminated by 5 antineoplastic agents.

Healthcare facilities are obligated to implement strategies to protect healthcare workers from exposure to hazardous drugs, including any real or potential risk from contaminated surfaces. Guidelines are broad and lack sufficient detail for healthcare facilities to establish clear effectiveness targets for their decontamination procedures. Our goal in this analysis was to measure the effectiveness of a decontamination procedure in a pharmacy buffer room contaminated with 5 antineoplastic drugs. Six rounds of contamination, decontamination, and wipe sampling were performed in a pharmacy buffer room designated for hazardous drug (HD) compounding. Ten locations in the buffer room were contaminated with 5-fluorouracil, carboplatin, cyclophosphamide, paclitaxel, and doxorubicin. Pharmacy staff were blinded to contamination sites. After contamination, 3 pharmacy technicians following the same decontamination procedure decontaminated the buffer room. To assess the impact of decontamination, residual hazardous drug levels were assessed after contamination and after decontamination using a commercially available wipe sampling product. The mean (SD) residual contamination levels for the 239 wipe samples taken before and after decontamination were 63 (60) ng and 3.9 (8.2) ng, respectively, representing a 94% reduction in residual HD contamination. Residual contamination was not detectable (<5 ng) in 221 (~93%) of the samples after decontamination. The employed decontamination procedures effectively reduced residual HD surface contamination.

Studying high-z galaxies with [C ii] intensity mapping

ABSTRACT We investigate the [C ii] line intensity mapping (IM) signal from galaxies in the Epoch of Reionization (EoR) to assess its detectability, the possibility to constrain the $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relation, and to recover the [C ii] luminosity function (LF) from future experiments. By empirically assuming that ${\rm log}\,L_{\rm C\,{\small II}}={\rm log}\,A+\gamma {\rm SFR}\pm \sigma _\mathrm{ L}$, we derive the [C ii] LF from the observed UV LF, and the [C ii] IM power spectrum. We study the shot noise and the full power spectrum separately. Although, in general, the shot-noise component has a much higher signal-to-noise ratio than the clustering one, it cannot be used to put independent constraints on log A and γ. Full power spectrum measurements are crucial to break such degeneracy and reconstruct the [C ii] LF. In our fiducial survey S1 (inspired by CCAT-p/1000 h) at z ∼ 6, the shot-noise (clustering) signal is detectable for two (one) of the five considered $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relations. The shot noise is generally dominated by galaxies with $L_{\rm C\,{\small II}}\gtrsim 10^{8}\!-\!10^{9}~ \mathrm{L}_\odot$ (MUV ∼ −20 to −22), already at reach of ALMA pointed observations. However, given the small field of view of such telescope, an IM experiment would provide unique information on the bright end of the LF. The detection depth of an IM experiment crucially depends on the (poorly constrained) $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relation in the EoR. If the $L_{\rm C\,{\small II}}\!-\!{\rm SFR}$ relation varies in a wide log A–γ range, but still consistent with ALMA [C ii] LF upper limits, even the signal from galaxies with $L_{\rm C\,{\small II}}$ as faint as ∼107 L⊙ could be detectable. Finally, we consider the contamination by continuum foregrounds (cosmic infrared background, dust, cosmic microwave background) and CO interloping lines, and derive the requirements on the residual contamination level to reliably extract the [C ii] signal.

Diagnostic screening of organic contaminant level in solidified/stabilized pre-treated oil-based drill cuttings

The reuse of solidified/stabilized low-temperature thermally desorbed (pre-treated) oil-based drill cuttings for construction purposes is becoming increasingly attractive in recent times; though, without screening a priori the levels of target residual organic contaminants against environmental guidelines to ensure compliance. In this study, pre-treated oil-based drill cuttings were collected from a waste treatment facility in the Niger Delta Province (5.317oN; 6.467oE), Nigeria and subjected to cement-based solidification/stabilization (S/S) followed by chemical leaching and screening of the data against local environmental guidelines. S/S was done with drill cuttings contents of 0 (control), 2, 4, 6, 8, and 10 % as part replacement for fine aggregate at 0.6:1, 0.65:1, 0.7:1, 0.75:1, and 0.8:1 water-to-cement ratios using 1:2:4 mix design for a grade-20 concrete. Afterwards, the surface microstructure, elemental composition, and unconfined compressive strength (UCS) of the solidified/stabilized matrix were determined. Amounts of heavy metals and total petroleum hydrocarbons (TPH) leached were also assessed. Results showed that the 2 % drill cuttings addition yielded the highest UCS (22.22–26.22 N/mm2) at water-to-cement ratio of 0.6:1, which were well above the recommended minimum UCS of 20 N/mm2 for a grade-20 concrete. The average amount of residual TPH in the solidified/stabilized matrix (62.41 mg/kg) was slightly higher than the local regulatory target value of 50 mg/kg; suggesting that the cement-based S/S failed to immobilize completely all the hydrocarbons in the pre-treated oil-based drill cuttings. This shows that the solidified/stabilized matrix is not in compliance with environmental guidelines on TPH for sustainable reuse as construction materials.

The application of biosurfactants for scouring wool

The first investigation of the use of biosurfactants for the scouring of raw wool is reported. A saponin, and a recently developed surface active oat extract, were evaluated at the laboratory scale using a first‐to‐be‐reported benchtop scouring system with simulated flowback. The levels of contaminants remaining on the wool after bioscouring, along with the wool colour, were compared with those of wool that had been laboratory‐scoured with a surfactant used in the commercial scouring of raw wool, namely a synthetic nine molar poly(oxyethylene)nonylphenyl (NPEO). Both biosurfactants can be extracted from land‐based renewable crops. The saponin proved to be effective, producing low levels of residual contaminants on the wool, and colours that were not statistically different to those of wool scoured with NPEO. The oat extract was considerably less effective than the saponin, both in terms of colour and residual contaminant level. This study demonstrated the significant potential of biosurfactants in the scouring of the global greasy wool clip, which now comprises two billion kg per annum.

Drumming-associated anthrax incidents: exposures to low levels of indoor environmental contamination

Two fatal drumming-related inhalational anthrax incidents occurred in 2006 and 2008 in the UK. One individual was a drum maker and drummer from the Scottish Borders, most likely infected whilst playing a goat-skin drum contaminated with Bacillus anthracis spores; the second, a drummer and drum maker from East London, likely became infected whilst working with contaminated animal hides.We have collated epidemiological and environmental data from these incidents and reviewed them alongside three similar contemporaneous incidents in the USA. Sampling operations recovered the causative agent from drums and drum skins and from residences and communal buildings at low levels. From these data, we have considered the nature of the exposures and the number of other individuals likely to have been exposed, either to the primary infection events or to subsequent prolonged environmental contamination (or both).Despite many individual exposures to widespread low-level spore contamination in private residences and in work spaces for extended periods of time (at least 1 year in one instance), only one other individual acquired an infection (cutaneous). Whilst recognising the difficulty in making definitive inferences from these incidents to specific residual contamination levels, and by extending the risk to public health, we believe it may be useful to reflect on these findings when considering future incident management risk assessments and decisions in similar incidents that result in low-level indoor contamination.

Ongoing environmental monitoring and assessment of the long-term impacts of the February 2014 radiological release from the waste isolation pilot plant.

Three years ago, the Waste Isolation Pilot Plant (WIPP) experienced its first minor accident involving a radiological release. Late in the evening on February 14, 2014, a waste container in the repository underwent a chemical reaction that caused the container to overheat and breach, releasing its contents into the underground. Following a lengthy recovery process, the facility recently resumed waste disposal operations. The accident released significant levels of radioactivity into the disposal room and adjacent exhaust drifts, and although no one was present in the underground at the time of the release, a total of 22 workers tested positive for very low level of radiation, presumably from some of the radioactive material that was released above ground through a small leak in the HEPA filtration system. The dominant radionuclides released were 241Am and 239 + 240Pu in a ratio that matched the content of the drum from Los Alamos National Laboratory (LANL) that was eventually identified as the breached container. From the air particulate monitoring and plume modeling, it was concluded that the dose, at the nearest location accessible to the general public, from this radiation release event would have been less than 0.01mSv (< 1mrem/year). This level is well below the 0.1mSv/year (10mrem/year) regulatory limit for DOE facilities established by the US Environmental Protection Agency (EPA).While no long-term impacts to public health or the environment are expected as a result of the WIPP radiation release, the limited ventilation and residual contamination levels in the underground are still a concern and pose a major challenge for the full recovery of WIPP. This article provides an up-to-date overview of environmental monitoring results through the WIPP recovery and an estimate of the long-term impacts of the accident on the natural and human environment.

Impressions of Hazmat Suits Based on Color

Background: Commonly, skin and clothing surface contamination screening (radiation survey) is performed for residents of an area to confirm the levels of residual contamination after nuclear power disasters. Examiners for such a screening often wear white radiation hazmat suits. However, it has been reported that examinees tend to feel tension or anxiety. In this study, we focus on the color of the radiation hazmat suit as one measure to reduce residents’ tension or anxiety. This study aims to determine the common conceptions of radiation hazmat suits based on color. Methods: An anonymous self-administered questionnaire survey was conducted with a total of 262 participants consisting of nursing students, administrative staff of a university, general citizens, and mothers raising their children in the Tohoku region in Japan. The common impressions of radiation hazmat suits, which are typically white, were measured using the Multiple Affective States Scale. This scale can measure the affective state brought about by clothing. The color of white (W) was defined as a standard color commonly used for hazmat suits; in order to determine the common impressions of radiation hazmat suits based on color, the following additional colors were shown to the participants: salmon pink (P), ivory (I), and light green (G). Results: There were no sex differences regarding common impressions of radiation hazmat suits. For white radiation hazmat suits, a high score reflecting the characteristic of “capable” was obtained, while the scores for “cheerful” and “calm” were low, and those for “depressed” and “tense” were high. The colors that showed the highest score for “calm” as a positive affirmative state were I and P. W and P reflected a high “ashamed” score, and the “tense” score for G was higher for the participants in their 20s than for those in their 30s and older. Conclusions: Results show that the color of hazmat suits provokes far greater feelings of anxiety and tension on participants than previously thought. Radiation hazmat suits may be further improved based on the results of this study.

Evaluation of Surface Cleaning Procedures for CTGS Substrates for SAW Technology with XPS.

A highly efficient and reproducible cleaning procedure of piezoelectric substrates is essential in surface acoustic waves (SAW) technology to fabricate high-quality SAW devices, especially for new applications such SAW sensors wherein new materials for piezoelectric substrates and interdigital transducers are used. Therefore, the development and critical evaluation of cleaning procedures for each material system that is under consideration becomes crucial. Contaminants like particles or the presence of organic/inorganic material on the substrate can dramatically influence and alter the properties of the thin film substrate composite, such as wettability, film adhesion, film texture, and so on. In this article, focus is given to different cleaning processes like SC-1 and SC-2, UV-ozone treatment, as well as cleaning by first-contact polymer Opticlean, which are applied for removal of contaminants from the piezoelectric substrate CaTaGaSiO. By means of X-ray photoelectron spectroscopy, the presence of the most critical contaminants such as carbon, sodium, and iron removed through different cleaning procedures were studied and significant differences were observed between the outcomes of these procedures. Based on these results, a two-step cleaning process, combining SC-1 at a reduced temperature at 30 C instead of 80 C and a subsequent UV-ozone cleaning directly prior to deposition of the metallization, is suggested to achieve the lowest residual contamination level.

EoR imaging with the SKA: the challenge of foreground removal

Abstract21-cm observations of the Cosmic dawn (CD) and Epoch of Reionization (EoR) are one of the high priority science objectives for SKA Low. One of the most difficult aspects of the 21-cm measurement is the presence of foreground emission, due to our Galaxy and extragalactic sources, which is about four orders of magnitude brighter than the cosmological signal. While end-to-end simulations are being produced to investigate in details the foreground subtraction strategy, it is useful to complement this thorough but time-consuming approach with simpler, quicker ways to evaluate performance and identify possible critical steps. In this work, I present a forecast method, based on Bonaldi et al. (2015), Bonaldi &amp; Ricciardi (2011), to understand the level of residual contamination after a component separation step, and its impact on our ability to investigate CD and EoR.

Evaluation of an enhanced cleaning and disinfection protocol in Salmonella contaminated pig holdings in the United Kingdom.

Salmonella is the second most commonly reported zoonotic gastrointestinal pathogen in the European Union, and a significant proportion of the cases are linked to the consumption of contaminated pork. Reduction of Salmonella at the farm level helps to mininimise the contamination pressure at the slaughterhouse, and therefore the number of Salmonella bacteria entering the food chain. Cleaning and disinfection (C&D) between batches of pigs is an intervention measure that has potential to reduce the transmission of Salmonella contamination within farms. In this study, two pig finisher buildings in each of 10 Salmonella positive farms were sampled pre-C&D, post-C&D, post-restocking with the following batch of pigs, and shortly before these pigs were sent to slaughter. The incoming batch of pigs was also sampled before it reached the study building (pre-restocking). At each visit, pooled and individual faecal samples were collected and Salmonella isolation was carried out according to an ISO 6579:2002 Annex D-based method. One building on each farm (intervention) was cleaned and disinfected according to a rigorous protocol consisting of several steps and a Defra-approved disinfectant used at the General Orders concentration, whilst the other building (control) was cleaned and disinfected as per normal farm routine. At the post-C&D visit, Enterobacteriaceae and total bacterial counts were determined to evaluate residual faecal contamination and general hygiene levels. Rodent specialists visited the farms before and after C&D and rodent carcasses were collected for Salmonella testing. The intervention buildings were significantly less likely (p = 0.004) to be positive for Salmonella after C&D. The pre-restocking pigs had the highest likelihood (p<0.001) of being Salmonella positive (often with multiple serovars) and there was no significant difference between intervention and control buildings in Salmonella prevalence at the post-restocking visit (p = 0.199). However, the pigs housed in the intervention buildings were significantly less likely (p = 0.004) to be positive for Salmonella at slaughter age. Multivariable analysis suggested that cleaning all fixtures of buildings, leaving the pens empty for 2–3 days and using an effective disinfectant are factors significantly improving the likelihood of removing Salmonella contamination during C&D. Signs of rodents were recorded in all farms, but rodent activity and harbourage availability decreased between visits. All the rats tested were Salmonella negative. S. Typhimurium or its monophasic variants were isolated from 6 mouse carcasses in 3 farms where the same serovars were isolated from pigs. This study demonstrates that an appropriate C&D programme significantly reduces the likelihood of residual contamination in Salmonella positive pig buildings, and suggests a significant reduction in the prevalence of Salmonella in the pigs in appropriately cleaned and disinfected buildings when sampled before slaughter. Due to a high prevalence of infection in replacement pigs, control of Salmonella in pig farms is challenging. Rodents may also contribute to the carry-over of infection between batches. C&D is a useful measure to help reduce the number of infected pigs going to the slaughterhouse, but should be supplemented by other control measures along the pig breeding and production chain.

Chelation-directed C-H activation/C-C bond forming reactions catalyzed by Pd(ii) nanoparticles supported on multiwalled carbon nanotubes.

Chelation-directed C-H activation/C-C bond forming reactions utilizing homogeneous palladium(ii) and the Pd(ii)/Pd(iv) catalytic cycle have been previously reported. Here we report the first use of a solid-supported Pd(ii) catalyst [Pd(ii) nanoparticles on multiwalled carbon nanotubes, Pd(ii)/MWCNT] to carry out C-H activation/C-C bond forming reactions. The results presented demonstrate that the solid-supported Pd(ii)/MWCNT catalyst can effectively catalyze these arylation reactions using the Pd(ii)/Pd(iv) catalytic cycle. We also show that the solid-supported catalyst is recyclable, has turnover frequencies up to 2.9-fold higher than the homogeneous catalyst, and results in low levels of residual palladium contamination in the products.

Challenging Residual Contamination of Instruments for Robotic Surgery in Japan.

BACKGROUND Recently, robotic surgery has been introduced in many hospitals. The structure of robotic instruments is so complex that updating their cleaning methods is a challenge for healthcare professionals. However, there is limited information on the effectiveness of cleaning for instruments for robotic surgery. OBJECTIVE To determine the level of residual contamination of instruments for robotic surgery and to develop a method to evaluate the cleaning efficacy for complex surgical devices. METHODS Surgical instruments were collected immediately after operations and/or after in-house cleaning, and the level of residual protein was measured. Three serial measurements were performed on instruments after cleaning to determine the changes in the level of contamination and the total amount of residual protein. The study took place from September 1, 2013, through June 30, 2015, in Japan. RESULTS The amount of protein released from robotic instruments declined exponentially. The amount after in-house cleaning was 650, 550, and 530 µg/instrument in the 3 serial measurements. The overall level of residual protein in each measurement was much higher for robotic instruments than for ordinary instruments (P<.0001). CONCLUSIONS Our data demonstrated that complete removal of residual protein from surgical instruments is virtually impossible. The pattern of decline differed depending on the instrument type, which reflected the complex structure of the instruments. It might be necessary to establish a new standard for cleaning using a novel classification according to the structural complexity of instruments, especially for those for robotic surgery. Infect Control Hosp Epidemiol 2017;38:143-146.

Investigation into cross-contamination during cleaning efficiency testing in PET recycling

The cleaning efficiency of a PET recycling process is typically investigated by artificial contamination of post-consumer PET flakes within a so-called challenge test. Challenging of pilot plants or industrial scale lines is done be introducing a certain amount of contaminated flakes while running the process with non-contaminated flakes of different colour. After decontamination the contaminated flakes are separated from the non-contaminated flakes and only the contaminated flakes were analysed due to their residual contamination level. The European Food Safety Authority (EFSA), however, raised the question about cross-contamination, which might reduce the overall cleaning efficiency of the recycling process. Cross-contamination is defined as the transfer of surrogate contaminants from the initially contaminated to the initially not contaminated material during a challenge test. Data for the phenomenon of cross-contamination are not available in the scientific literature. Aim of the study was to close this gap by providing experimental data for cross-contamination by use of several challenge tests. As a result cross-contamination was found only at ratios of 1:1 between contaminated and non-contaminated PET flakes. At higher ratios which were typically applied in challenge tests on pilot plant or industrial scale line cross-contamination do not play a significant role. In addition, the results show that cross-contamination is negligible for volatile compounds.

Challenging the Limit of Detection for Egg Allergen Detection in Red Wines by Surface Plasmon Resonance Biosensor

The improvement of a surface plasmon resonance (SPR)-based immunoassay for the detection of traces of egg-based fining agents in red wines is herein described. The latter represents an extension of a previously developed direct assay targeted to the detection of ovalbumin (OVA) as marker of the presence of egg white powder residues, a typical fining agent utilized by the winery industry. In this paper, a suitable pre-treatment procedure was optimized for the sensitive detection of OVA at sub-ppm levels in red wines fortified with egg-white powder, by using an immunoassay proved to be reliable for both white and rosee wines. A red wine from Chianti grapes selected as reference matrix was artificially contaminated with egg-white powder before undergoing different sample purification. Several purification strategies were investigated and tested in order to challenge the limit of detection (LOD) obtained with the methods currently in use for egg allergen detection. Finally, the optimized two-step pre-treatment, combining polyvinylpolypyrrolidone-based purification and size exclusion chromatography, enabled to achieve an LOD in red wine as low as 0.2 μg/mL. The optimized SPR-based method met the method performance criteria issued by the International Organization of Vine and Wine (OIV) concerning the minimum sensitivity required for the analyses of potentially allergenic fining agent proteins in wines, confirming the biosensor as promising tool to monitor the residual contamination level of fined red wines.