Deep Cleaning Research Articles

Deep Cleaning of Crystal Violet and Methylene Blue Dyes from Aqueous Solution by Dextran-Based Cryogel Adsorbents.

Polysaccharides have recently attracted growing attention as adsorbents for various pollutants, since they can be extracted from a variety of renewable sources at low cost. An interesting hydrophilic and biodegradable polysaccharide is dextran (Dx), which is well-known for its applications in the food industry and in medicine. To extend the application range of this biopolymer, in this study, we investigated the removal of crystal violet (CV) and methylene blue (MB) dyes from an aqueous solution by Dx-based cryogels using the batch technique. The cryogel adsorbents, consisting of cross-linked Dx embedding a polyphenolic (PF) extract of spruce bark, were prepared by the freeze-thawing approach. It was shown that the incorporation of PF into the Dx-based matrix induced a decrease in porosity, pore sizes and swelling ratio values. Moreover, the average pore sizes of the DxPF cryogels loaded with dyes further decreased from 42.30 ± 7.96 μm to 23.68 ± 2.69 μm, indicating a strong interaction between the functional groups of the cryogel matrix and those of the dye molecules. The sorption performances of the DxPF adsorbents were evaluated in comparison to those of the Dx cryogels and of the PF extract. The experimental sorption capacities of the DxPF cryogel adsorbents were higher in comparison to those of the Dx cryogels and the PF extract. The DxPF cryogels, particularly those with the highest PF contents (sample DxPF2), demonstrated sorption capacities of 1.2779 ± 0.0703 mmol·g-1, for CV, and 0.3238 ± 0.0121 mmol·g-1, for MB. The sorption mechanisms were analyzed using mathematical models, including Langmuir, Freundlich, Sips and Dubinin-Radushkevich isotherms, and kinetic models, like pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich and intra-particle diffusion (IPD). The sorption process was best described by the Sips isotherm and PSO kinetic models, indicating chemisorption as the dominant mechanism. This study outlines the importance of developing advanced renewable materials for environmental applications.

Life After Plastic-Wrapped Bodies: COVID, the State and the Crisis of Social Reproduction in Rural South Africa

ABSTRACT: This article explores the impact and implications of the South African state’s adoption of a tough militarized, bio-medical, and essentially neo-colonial approach to the management of the COVID pandemic in the rural former Bantustans (“native reserves”) of the country. It argues that, while the “war on COVID” produced new national legislation for all citizens, those living “with custom” in former homelands were said to possess cultural attributes that amplified the risk of infection and death. The paper focuses on how the state constructed measures for these spaces and managed social interaction and burials in the migrant heartlands. The paper suggests that families “living with custom” in the former homelands were treated differently from other citizens, existing in what Giorgio Agamben (2004) might call a “state of (greater) exception.” Villagers used the metaphor of the gate closing on them (ukuvala isango) to describe their experience and exclusion during lockdown as customary practices were banned, local health facilities closed for deep cleaning, and bodies sealed in plastic at state hospitals and mortuaries. The latter measures disturbed rural families much more than police violence or the closure of government clinics because it presented a serious threat to social reproduction. The paper provides evidence of how families fought to restore conviviality by exhuming the bodies wrapped in plastic to allow them to communicate with kin and ancestors. It also shows how, after lockdown, vaccination was often treated as a family matter not an individual choice, and how families moved quickly to fix the spiritual insecurities wrought by COVID. The paper concludes with a harrowing account of the new epidemic of hunger and malnutrition that is stalking these landscapes as conviviality is not enough to secure survival. The paper highlights the limits of narrow bio-medical and individual rights-based approaches in dealing with health, livelihoods, and well-being in communities devastated by COVID in rural southern Africa.

Determination of non-combustible impurities in detonation nanodiamond powder

The study of the physicochemical (including adsorption) properties of nanodiamond requires the possibility of reproducible generation of the carbon surface of an individual particle without metal impurities of unknown composition. This kind of surface can be obtained through an additional deep cleaning of a commercially available sample. This article is dedicated to the study of the composition of non-combustible impurities of detonation nanodiamond powder. Using inductively coupled plasma mass spectrometry, iron and titanium were identified as the main metal components of the unburned residue, and the presence of Cr, Ni, Zr, As, and Sb was qualitatively established. The expected composition of the main molecular ions formed on the surface of the unburned residue in the course of laser desorption/ionisation mass spectrometry was presented. Based on the results of mass spectrometry analysis, a method of two-stage chemical treatment of detonation nanodiamond powder was proposed, which allowed reducing the mass fraction of non-combustible impurities during annealing in air from 2.0 to 0.1%.

Influence of cohesive clay on wave–current ripple dynamics captured in a 3D phase diagram

Abstract. Wave–current ripples that develop on seabeds of mixed non-cohesive sand and cohesive clay are commonplace in coastal and estuarine environments. While laboratory research on ripples forming in these types of mixed-bed environments is relatively limited, it has identified deep cleaning, the removal of clay below the ripple troughs, as an important factor controlling ripple development. New large-scale flume experiments seek to address this sparsity in data by considering two wave–current conditions with initial clay content, C0, ranging from 0 % to 18.3 %. The experiments record ripple development and pre- and post-experiment bed clay contents to quantify clay winnowing. The present experiments are combined with previous wave-only, wave–current, and current-only experiments to produce a consistent picture of larger and smaller flatter ripples over a range of wave–current conditions and C0. Specifically, the results reveal a sudden decrease in the ripple steepness for C0 > 10.6 %, likely associated with a decrease in hydraulic conductivity of 3 orders of magnitude. Accompanying the sudden change in steepness is a gradual linear decrease in wavelength with C0 for C0 > 7.4 %. Ultimately, for the highest values of C0, the bed remains flat, but clay winnowing still takes place, albeit at a rate 2 orders of magnitude lower than for rippled beds. For a given flow, the initiation time, when ripples first appear on a flat bed, increases with increasing C0. This, together with the fact that the bed remains flat for the highest values of C0, demonstrates that the threshold of motion increases with C0. The inferred threshold enhancement, and the occurrence of large and small ripples, is used to construct a new three-dimensional phase diagram of bed characteristics involving the wave and current Shields parameters and C0, which has important implications for morphodynamic modelling.

Using Spatial Modeling to Evaluate LED Light Intensity and Uniformity in Commercial Broiler Houses during Brooding and Tunnel Conditions

Highlights During brooding, more than 97% of the floor area of new broiler houses was above target light intensity, however, in aged houses less than 0.2% of the floor area was above the target. During tunnel conditions, less than 6% of the floor area met the target light intensity range (0.18–0.22 lx) for both aged and new houses. All floor areas in the fan section exceeded the target light intensity in both aged and new houses in all the farms due to light intrusion from the tunnel fans. Bulbs need to be periodically replaced to meet minimum target levels during brooding and light dimmer adjustments need to be made to meet light intensity targets during tunnel ventilation. Abstract. Commercial broiler companies set specific light intensities and photoperiods during different stages of live production to manage bird behavior and growth and to support health and welfare. However, it is currently unknown how much of the floor area in commercial houses is within the target levels set by companies. Therefore, a field survey of twenty 18.3 × 152.4 m broiler houses on five farms was performed to evaluate in-situ light intensity and uniformity in two house sections during brooding [evaporative pad section (pad) and the middle of the house section (mid)] and three sections during tunnel ventilation [pad, mid, and tunnel exhaust fan section (fan)]. Houses ranged in age from new (never used) to aged (5–8 years old). Light intensity measurements were recorded at 70 locations in each of the house sections (140 per house during brooding; 210 per house during tunnel). For tunnel mode, target light intensity values were categorized into above target (>0.22), within target (0.18–0.22 lx), and below target (<0.18 lx). For brooding mode, target light intensity values were below target (<43 lx) and within target (=43 lx). Geostatistics was used to map and calculate the percentage of floor area above, below, or within target thresholds. During brooding and tunnel conditions, the percent of floor area below target (<43 lx and <0.18 lx, respectively) was higher for aged houses than for new houses in the pad and midsections. All the floor area in the fan section was above target due to light intrusion from operating fans. During tunnel ventilation in the new houses, 4.5%, 6.0%, and 0.0% of the floor area at the pad, center, and fan sections, respectively, were within the 0.18 to 0.22 lx target threshold. However, in the aged houses, only 0.6%, 0.7%, and 0.0% of the floor area at the pad, center, and fan sections, respectively, were within the target range. This research illustrates that the newer houses did a better job at meeting or exceeding target light intensities and that very little of the floor area in new and aged houses during tunnel ventilation was within a 10% threshold of target intensities. Lack of light dimmer adjustment to account for lumen depreciation and accumulation of dust on the bulbs in the aged house most likely led to the lower overall light intensities. Because brood bulbs have a 100% lumen capacity and are not dimmed, a deep cleaning of the bulbs and periodic replacement are recommended if they are not reaching lighting targets. Periodic checking of light intensity is recommended, especially in older houses. Keywords: Broilers, House age, Light intensity, Spatial variation, Target.

Maximum permissible technological parameters of frame-filling filters

Relevance. Wastewater of knitting industry contains various types of dyes, synthetic surfactants, mineral salts and suspended solids in values requiring deep cleaning. It is advisable to carry out deep cleaning of these drains on non-pressure filters, which do not require large expenses and are easy to operate. We gave preference to frame-filling filters. First of all, it allows significant increase in filtration rate, and its two layers with different fractions of filter materials significantly contributes to differentiated purification of wastewater from suspended solids of various sizes. Aim. To determine the maximum permissible values of technological parameters of the frame-filling filters operation (filtration rate and duration of the filter cycle) at which high filtration effect is provided through a highly porous material-crushed expanded clay. Objects. Wastewaters of the knitting industry and the effluents of the cotton and textile industries that are similar in their composition of pollution, as well as the identical effluents of some other branches of light industry. Methods. The experimental method was used on a laboratory frame-filling filter installation. The expanded clay used was obtained by the method of swelling low-melting clays and clay rocks during their rapid firing, followed by crushing to the state of sand. In general, the proposed technological methods are justified by those comparative and generalizing methods that can improve frame-filling filter operation. Results and conclusions. Based on the results of the conducted research, the following conclusions can be drawn: Pronounced intergranular porosity (on average 1.6 times greater than that of quartz sand) allows expanded clay granules passing through a significant amount of waste water at relatively high filtration speeds (20–22 m h) and retain up to 70% of suspended solids The duration of the filter cycle when using crushed expanded clay is at least 1.5 times longer than when using quartz sand Due to the greater difference in the average coefficients of the shape of the filtering materials, more complete regeneration of filtering properties of crushed expanded clay compared to quartz sand is provided 2–3 minutes earlier, regardless of the initial concentration of suspended substances. The filtering properties of crushed expanded clay during deep wastewater treatment of the knitted production with the main concentrated pollution indicators (color intensity, BODfull, COD and surfactants) practically do not concede the quartz sand properties. Besides, crushed expanded clay is much cheaper than quartz sand; it can be used on an equal footing with quartz sand for deep cleaning of low-turbidity and slightly colored industrial wastewater.

A Survey on Core Flow Cytometry Facilities: Instrument Maintenance, Usage, and Funding.

Flow cytometry is a powerful tool that finds applications in various fields such as immunology, molecular biology, cancer biology, virology, and infectious disease monitoring. A significant portion of the research in these disciplines is supported by flow cytometry shared resource laboratories (SRLs). There are several types of flow cytometers available for use in SRLs, including analyzers, sorters, imaging flow cytometers, and mass cytometers. Each type has different challenges when it comes to maintenance and life expectancy. An independent online survey was conducted to better understand instrument maintenance and turnover in flow cytometry SRLs. Questions regarding instrument uptime (availability), its usage, routine maintenance, and cost associated with it were addressed. The respondents also answered questions pertaining to the frequency of deep cleaning of the instrument and quality control. In addition, the survey queried about the source of funding used to purchase the instruments and possible reasons for a replacement. Presented herein are the results compiled from 146 core facilities that provide a look at the operation within a typical SRL, with the responses reflecting researchers' experiences with handling flow cytometers.

Evaluating transit mode choice in the context of the COVID-19 pandemic – A stated preference approach

The COVID-19 pandemic and its accompanying restrictions reduced travel demand globally. Public transit ridership was significantly affected, causing transit agencies to lose fare revenue and reduce service. Although transit ridership has recovered significantly since the worst of the pandemic, it is still reduced in many cities. Transit agencies can benefit from understanding how to increase post-pandemic mode share and prepare for future health crises. This paper presents the design and findings of a stated preference (SP) survey conducted in Calgary, Canada to investigate the effects of different safety measures, pandemic risk levels, transit service characteristics, crowding, and demographics on the attractiveness of transit. SP scenarios were generated using Bayesian D-efficient design and were pivoted on respondents’ answers to previous questions. A multinomial logit model and a mixed logit model were estimated using the survey results. The model estimations show that transit agencies can attract riders by implementing mandatory masking policies and reducing in-vehicle crowding. Safety policies such as backdoor boarding and daily deep cleaning are unlikely to attract riders to transit. Higher pandemic risk levels, as measured by the daily number of cases in the study area, decrease the attractiveness of transit. Females and older respondents perceived transit modes as less attractive compared to males and younger respondents. Respondents who had been at least partially vaccinated perceived transit as more attractive compared to those who were unvaccinated. The results of this project can guide transit agencies in the event of future pandemics or health crises.

Removal of undissolved substances in the dissolution-based recycling of polystyrene waste by applying filtration and centrifugation

Polystyrene (PS) is a versatile polymer typically used in applications such as yogurt cups, packaging trays, disk cases and toys. To increase recycling rates of PS, dissolution recycling is being investigated, which involves the liquefication of the polymer in a suitable solvent, allowing deep cleaning of the polymer from impurities. Quite specific to PS is that polystyrene waste contains both general-purpose polystyrene and high-impact polystyrene (HIPS), which is composed of free PS and polystyrene-grafted polybutadiene particles. In this work the potential of filtration and centrifugation is analyzed with the aim of cleaning the polymer from both, insoluble PB-PS particles and pigments (TiO2, Cr/Sb/Ti oxide and carbon black). The dead-end lab scale filtration were performed at room temperature and at pressures between 1.5 and 30 bar. The pigments were successfully removed, yet, filtration of HIPS solutions results in low fluxes due to extreme membrane fouling caused by the PB-PS particles, which was confirmed by the application of pore-blockage filtration models. Alternatively, centrifugation at 14,052 G-force has shown to be a promising alternative to separate the particles from HIPS, resulting in 100% turbidity reduction. Equally, the separation of pigments was successful, highlighting that TiO2 and Cr/Sb/Ti oxide have shorter sedimentation times compared to carbon black. Finally, the two separation processes are tested on a PS rigid packaging waste sample coming from a sorting line and the results show that centrifugation allows a high turbidity reduction and that a two-step separation process starting with centrifugation for PB-PS particles removal can facilitate further downstream cleaning.

Hydrogen Sulphide and Carbonyl Sulphide Removal from Biogas for Exploitation in High-Temperature Fuel Cells

Fuel cells powered by biogas for decentralised cogeneration of heat and power are an attractive alternative to combustion technologies. However, biogas contains sulfur-based compounds (H2S, COS, DMS, siloxanes), which are harmful to fuel cells. This work was carried out in the framework of the European project Waste2Watts, involving the laboratories of Politecnico di Torino, ENEA, and PSI. The aim is to design and test a flexible and cost-effective cleaning unit to remove impurities for the use of biogas in high-efficiency fuel cell systems. The focus is on small- to medium-sized farms for which deep cleaning of biogas by adsorption materials is a suitable techno-economic solution to avoid intensive gas processing treatments. The ability of commercial adsorption materials (activated carbons, metal oxides, and metal hydroxides) to remove hydrogen sulphide and carbonyl sulphide was tested under different biogas compositions (oxygen and humidity). After evaluating the results, three plant configurations were proposed to optimally utilise the potential of the sorbents. Indeed, the RGM3 sorbent has proven to be an effective solution for removing H2S and COS under humid conditions (50% RH), whilst R7H and R8C sorbents are better suited for removing H2S and COS, respectively, in dry biogas conditions.Graphical abstract

Mycobacterium chimaera infections in cardiothoracic surgery patients exposed to heating and cooling devices despite infection control measures

Background: LivaNova 3T heating and cooling devices (HCDs) have been associated with Mycobacterium chimaera, a Mycobacterium avium-intracellulare (MAIC) species, infections after cardiothoracic surgery. We describe our outbreak, which persisted despite escalating infection control measures. Methods: We identified patients with a positive MAIC culture following cardiothoracic surgery from January 2015 to the present at our institution. We classified these as “definite,” “possible,” or “operating room contamination” cases based on positive cultures from sterile sites, airway, or surgical specimens without evidence of infection. To identify patient or surgery characteristics associated with risk for MAIC infection, we conducted a case–control study comparing definite cases to randomly selected unmatched controls of patients over the same period without a positive MAIC culture after cardiothoracic surgery. Results: We identified 26 patients with a positive MAIC culture after cardiothoracic surgery: 13 definite, 9 possible, and 4 contamination cases. Among definite cases, the most common surgeries were valve replacements and left ventricular assist devices (5 cases each). The mean time from cardiothoracic surgery to diagnosis was 525 days. Overall, 10 (77%) cases occurred after exposure to our oldest HCDs (manufactured in 2013 or earlier). To date, 16 (62%) have undergone or are undergoing treatment for MAIC infection, and 4 (15%) have died due to NTM infection or complications. Compared to 47 controls, definite cases were associated with chronic kidney disease, implants, procedure type, use of cardiopulmonary bypass, and HCD age. Cases were not associated with time on bypass, time in the operating room, or other comorbid conditions (Table). All cases occurred despite enhanced disinfection and reorienting the HCD within the operating room, according to manufacturer recommendations. Moreover, 18 cases, including 7 definite cases, occurred after most HCDs were either deep cleaned or upgraded by the manufacturer. Also, 5 cases, including 3 possible cases and 2 contamination cases, occurred after physical separation of the HCD from the operating room. In August 2022, we purchased a fleet of glycol-cooled HCDs, and we have not identified additional MAIC cases since their deployment (Fig.). Conclusions: MAIC infections after cardiothoracic surgery were associated with procedure type, especially implants, use of cardiopulmonary bypass, and HCD age. Contrary to prior reports, neither operative nor CPB time was associated with MAIC infection after cardiothoracic surgery. The outbreak persisted despite disinfection and/or deep cleaning and reorienting HCDs within the operating room; some possible and contamination cases occurred even after moving HCDs outside the operating room. Thus, HCD water contamination events in the operating room (eg, spills from HCD tubing) may be a route of exposure, and different infection prevention measures are needed.Disclosure: None

Developing better understanding of hygiene is key to developing hygiene behaviour change in home and everyday life settings

Polling indicates the public has fairly good knowledge of times when hygiene is needed in their homes and everyday life in public spaces, but limited understanding of hygiene risk; this results in omitting some key behaviours and incorrectly applying untargeted behaviours. This poll explores how the public responded to government advice, and information from other sources, to address a specific disease threat - that is, COVID-19 infection. An online poll was developed, and data were collected from 1730 respondents in England aged 18 and above. Data suggest that the UK public has a high level of concern about the importance of hygiene to prevent spread of COVID-19. They had good recall of advice given during the pandemic and were able to identify routes of infection transmission. When asked to identify key times for handwashing, most people (86%-90%) identified 'after coughing, sneezing etc., before eating food with fingers, after touching contact surfaces and when returning home', but a similar number also identified using the toilet, food handling and pet handling, despite the fact that government advice does not identify these as risk actions for COVID-19. This suggests they were unable to use their knowledge of how the virus spreads to make informed decisions about when to practice hygiene. Despite government guidance, public practices are still influenced by a conviction that deep cleaning, including non-targeted disinfectant usage on environmental surfaces, gives added protection, leading them to practise additional cleaning and disinfection in situations where there is little benefit. New insights from public polling, together with the nine moments Targeted Hygiene approach, offer a more robust communications approach to enable the public to make cognitive links between when, where, how and why to practise good hygiene, and in doing so, promote more effective and sustainable behaviours.

A Global Review of the Impacts of the Coronavirus (COVID-19) Pandemic on Radiology Practice, Finances, and Operations.

The Coronavirus Disease 2019 (COVID-19) pandemic ushered in rapid changes in healthcare, including radiology, globally. This review discusses the impact of the pandemic on various radiology departments globally. We analyze the implications of the COVID-19 pandemic on the imaging volumes, finances, and clinical operations of radiology departments in 2020. Studies from health systems and outpatient imaging centers were analyzed, and the activity throughout 2020 was compared to the pre-pandemic activity, including activity during similar timeframes in 2019. Imaging volumes across modalities, including MRI and CT scans, were compared, as were the Relative Value Units (RVUs) for imaging finances. Furthermore, we compared clinical operations, including staffing and sanitation procedures. We found that imaging volumes in private practices and academic centers decreased globally. The decreases in volume could be attributed to delayed patient screenings, as well as the implementation of protocols, such as the deep cleaning of equipment between patients. Revenues from imaging also decreased globally, with many institutions noting a substantial decline in RVUs and revenue compared with pre-COVID-19 levels. Our analysis thus found significant changes in the volumes, finances, and operations of radiology departments due to the COVID-19 pandemic.

Assessing the Impact of COVID-19 Pandemic on the Domestic Water Usage of Local Communities in Hanoi, Vietnam

This study aims to better understand the changes in the water usage behaviors of Hanoi communities in the current circumstance of preventing the spread of COVID-19 pandemic and developing the economy. The results of 206 survey responses conducted during April 2022 show that the main changes in the domestic water usage behavior of Hanoi communities come from hand washing, bathing/personal hygiene, house cleaning, and clothes washing. During the pandemic, 77% of the respondents had a habit of washing their hands for 30 seconds as recommended by the Ministry of Health and the frequency of daily hand washing increased 5-7 times compared to before the pandemic. The frequency of housing deep cleaning increased by 33% compared to before the pandemic, besides the frequency of floor mopping also increased about 3.5 times per week. The average frequency of clothes washing also changed from 2.43 times/week to 4.61 times/week. The total estimated moderate water use per person increased by 1.41% compared to its before the pandemic. Therefore, based on the total population of Hanoi city, the amount of domestic water increased by 471.457 m3/day. Statistical results show that there are differences in most of the water usage behaviors between the two groups of people living in apartments and houses.
 
 
 

Synthesis, Characterization, Cytotoxicity Analysis and Evaluation of Novel Heterocyclic Derivatives of Benzamidine against Periodontal Disease Triggering Bacteria.

Periodontal disease (PD) is multifactorial oral disease that damages tooth-supporting tissue. PD treatment includes proper oral hygiene, deep cleaning, antibiotics therapy, and surgery. Despite the availability of basic treatments, some of these are rendered undesirable in PD treatment due to side effects and expense. Therefore, the aim of the present study is to develop novel molecules to combat the PD triggering pathogens. The study involved the synthesis of 4-((5-(substituted-phenyl)-1,3,4-oxadiazol-2-yl)methoxy)benzamidine (5a-e), by condensation of 2-(4-carbamimidoylphenoxy)acetohydrazide (3) with different aromatic acids; and synthesis of 4-((4-(substituted benzylideneamino)-4H-1,2,4-triazol-3-yl)methoxy)benzamidine (6a-b) by treatment of compound 3 with CS2 followed by hydrazination and a Schiff reaction with different aromatic aldehydes. Synthesized compounds were characterized based on the NMR, FTIR, and mass spectrometric data. To assess the effectiveness of the newly synthesized compound in PD, new compounds were subjected to antimicrobial evaluation against P. gingivalis and E. coli using the micro-broth dilution method. Synthesized compounds were also subjected to cytotoxicity evaluation against HEK-293 cells using an MTT assay. The present study revealed the successful synthesis of heterocyclic derivatives of benzamidine with significant inhibitory potential against P. gingivalis and E. coli. Synthesized compounds exhibited minimal to the absence of cytotoxicity. Significant antimicrobial potential and least/no cytotoxicity of new heterocyclic analogs of benzamidine against PD-triggering bacteria supports their potential application in PD treatment.

Commissioning new operation theatres by microbiological air sampling

Introduction: Ensuring air quality in operation theatres is of paramount importance to prevent surgical site infections. Microbiological commissioning number of new surgical theatres in our hospital, has been a challenging, yet also a rewarding experience to our staff. Methodology: A total of 19 new operation theatres including orthopaedic, neurosurgical, and cardiac theatres and associated sterile site areas were evaluated. Air sampling was followed by high level cleaning and running ventilation systems for 25 air changes per hour. Five samples were collected from each operation theatre. A sample of 1000L of air was aspirated on to 5% Horse Blood agar over 10 minutes. Colonies were enumerated following aerobic incubation at 37◦C for 24 and 48 hours. Results: During the first round of sampling 73% of samples yielded satisfactory (≤10 CFU/m3) results. A second round of samples following deep cleaning was required to certify remaining theatres. Conclusion: Microbiological testing and commissioning of our new operation theatres enabled us to certify our new operation theatres locally.

Navajo Nation Stores Show Resilience During COVID-19 Pandemic.

On April 8, 2020, the Navajo Nation issued an administrative order limiting business operations. Facing high coronavirus disease 2019 (COVID-19) rates and limited food infrastructure, a survey was conducted among Navajo Nation store managers to assess: (1) COVID-19 adaptations; (2) challenges; (3) changes in customer volume and purchasing; and (4) suggestions for additional support. Purposive sampling identified 29 stores in Navajo communities. Representatives from 20 stores (19 store managers/owners, 1 other; 7 grocery, and 13 convenience/other stores) were interviewed by phone or in-person to reach saturation (new information threshold < 5%). Responses were coded using frequencies and inductive thematic analysis. All 20 stores implemented COVID-19 guidelines (Centers for Disease Control and Prevention [CDC]/Navajo Nation) and most received orientation/support from local chapters, community organizations, or health centers. Stores implemented staff policies (50%, handwashing, vaccinations, protective personal equipment (PPE), sick leave, temperature checks), environmental changes (50%, hand sanitizer, checkout dividers), customer protocols (40%, limit customers, mask requirements, closed restrooms), and deep cleaning (40%). Most stores (65%) reported challenges including stress/anxiety, changing guidelines, supply chain and customer compliance; 30% reported infection or loss of staff. Weekday customer volume was slightly higher vs. pre-COVID, but weekend lower. Stores reported consistent or more healthy food purchases (50%), more nonfood essentials (20%), or shelf-stable foods (10%). Desired support included further orientation (30%), leadership support (20%), overtime/time to learn guidelines (20%), and signage/handouts (15%). Despite a high COVID-19 burden and limited food store infrastructure, Navajo Nation stores adapted by implementing staff, environmental and customer policies. Local support, staffing, and small store offerings were key factors in healthy food access.

Resistant invasive Candida auris reported in neutropenic patients treated successfully with three antifungals

Candida auris is a deadly fungal pathogen able to cause fatal symptoms in immunocompromised patients. It may be misidentified and difficult to clinically diagnose. The guidelines are to employ Echinocandin and Amphotericin B in the treatment, but the following study elucidates successful treatment of infection by a combination of three classes of antifungal drugs; never reported before. We present a patient with fulminant acute disseminated encephalomyelitis and neutropenia who developed invasive candidiasis despite appropriate antifungal therapy. We successfully treated ongoing candidemia with three antifungal drugs which lead to the resolution of fungemia after 18 days of treatment. Isolation, segregation, waste disposal, and deep cleaning technique were also followed as recommended by the Infectious Diseases Society of America guidelines. First report of Candidemia in an immunocompromised patient was successfully treated with three classes of antifungal drugs, IV Micafungin, Amphotericin B, and Posaconazole for nearly 18 days.

Discontinuity in Equilibrium Wave-Current Ripple Size and Shape and Deep Cleaning Associated With Cohesive Sand-Clay Beds.

Mixtures of cohesive clay and noncohesive sand are widespread in many aquatic environments. Ripple dynamics in sand-clay mixtures have been studied under current-alone and wave-alone conditions but not combined wave-current conditions, despite their prevalence in estuaries and the coastal zone. The present flume experiments examine the effect of initial clay content, C 0, on ripples by considering a single wave-current condition and, for the first time, quantify how changing clay content of substrate impacts ripple dimensions during development. The results show inverse relationships between C 0 and ripple growth rates and clay winnowing transport rates out of the bed, which reduce as the ripples develop toward equilibrium. For C 0≤10.6%, higher winnowing rates lead to clay loss, and thus the presence of clean sand, far below the base of equilibrium ripples. This hitherto unquantified "deep-cleaning" of clay does not occur for C 0>10.6%, where clay-loss rates are much lower. The clay-loss behavior is associated with two distinct types of equilibrium combined flow ripples: (a) Large asymmetric ripples with dimensions and plan geometries comparable to their clean-sand counterparts for C 0≤10.6% and (b) small, flat ripples for C 0>10.6%. The 10.6% threshold, which may be specific to the experimental conditions, corresponds to a more general 8% threshold found beneath the ripple base, suggesting that clay content here must be <8% for clean-sand-like ripples to develop in sand-clay beds. This ripple-type discontinuity comprises a threefold reduction in ripple height, with notable implications for bed roughness.

Removal of Inclusions using Swirling Flow in a Single-Strand Tundish

Swirling flow tundish was developed to enhance the coalescence of inclusions, so as to deeply clean the liquid steel. Inclusions would gather to the center of the swirling flow by centripetal force, due to the density difference between inclusions and liquid steel. Thus, small inclusions can coalesce into larger ones, and then float to the free surface by their self-buoyance. Physical experiments were carried out in a 1/2.5 scale single strand tundish to study the flow characteristics of tundish with swirling chamber. Numerical modeling was developed to simulate the movements of small inclusions in swirling flow. Discrete phase model was employed together with the O’Rourke algorithm to characterize the coalescence of the inclusions in the swirling flow. The removal of inclusions was investigated, considering the absorption by upper slag and trapping by outside wall of ladle shroud. Compared with a turbulence inhibitor, a swirling chamber shows a similar effect on flow improvement, while performs better in inclusion removal, owing to the inclusion coalescence caused by centripetal force. The results revealed that swirling chamber in diameter of 450 mm is an optimized scheme for deep cleaning of liquid steel, with only 1.66% of the inclusions flowing out of the tundish nozzle.