The deactivation of an NH3-SCR Cu-SAPO catalyst upon exposure to non-oxidizing conditions

Abstract A Cu-SAPO catalyst for NH3-SCR applications showed a significant loss of deNOx performance after exposure to oxygen-free conditions. The present work aims at elucidating the causes of the observed progressive deactivation by comparing different experimental procedures for the SCR activity tests. The adoption of an experimental protocol, which avoids the exposure to a non-oxidizing environment, ensured a stable activity of the Cu-SAPO catalyst. Moreover, treatment of the deactivated catalyst with an oxidizing mixture at 550 °C for 5 h enabled to partially recover the deNOx activity

Norovirus Outbreaks from Drinking Water

Norovirus contamination calls for viral monitoring of drinking water

Development and characterization of thermally stable supported V–W–TiOcatalysts for mobile NH–SCR applications

Vanadium based catalysts supported on a mixture of tungsten and titanium oxide (V2O5/WO3–TiO2) are known to be highly active for ammonia selective catalytic reduction (NH3–SCR) of NOx species for heavyduty mobile applications. However they are also known to be sensitive to high temperatures which leads to both sintering of the anatase TiO2 support and a first order phase transition to rutile at temperatures .600uC. Here we report our attempts to use SiO2 to stabilize the TiO2 anatase phase and to compare its catalytic activity with that of a non-stabilized V2O5/WO3–TiO2 catalyst after thermal aging up to 800uC. Detailed characterization using spectroscopic (Raman, UV–vis, X-ray absorption spectroscopy), scattering and techniques providing information on the catalytic surface (Brunauer–Emmet–Teller, NH3 adsorption) have also been performed in order to understand the impact of high temperatures on component speciation and the catalytic interface. Results show that non-stabilized V2O5/WO3–TiO2 catalysts are initially stable after thermal aging at 600uC but on heating above this temperature a marked drop in catalytic activity is observed as a result of sintering and phase transformation of Anatase into Rutile TiO2 and phase segregation of initially highly dispersed WO3 and polymeric V2O5 into monoclinic WO3 and V2O3 crystallites. Similar behavior was observed for the 4–5 wt-% of SiO2-stabilised sample after aging above 700uC, importantly therefore, offset by some y100uC in comparison to the unstabilised sample

Two Drinking Water Outbreaks Caused by Wastewater Intrusion Including Sapovirus in Finland

Drinking water outbreaks occur worldwide and may be caused by several factors, including raw water contamination, treatment deficiencies, and distribution network failure. This study describes two drinking water outbreaks in Finland in 2016 (outbreak I) and 2018 (outbreak II). Both outbreaks caused approximately 450 illness cases and were due to drinking water pipe breakage and subsequent wastewater intrusion into the distribution system. In both outbreaks, the sapovirus was found in patient samples as the main causative agent. In addition, adenoviruses and Dientamoeba fragilis (outbreak I), and noroviruses, astroviruses, enterotoxigenic and enterohemorragic Escherichia coli (ETEC and EHEC, respectively) and Plesiomonas shigelloides (outbreak II) were detected in patient samples. Water samples were analyzed for the selected pathogens largely based on the results of patient samples. In addition, traditional fecal indicator bacteria and host-specific microbial source tracking (MST) markers (GenBac3 and HF183) were analyzed from water. In drinking water, sapovirus and enteropathogenic E. coli (EPEC) were found in outbreak II. The MST markers proved useful in the detection of contamination and to ensure the success of contaminant removal from the water distribution system. As mitigation actions, boil water advisory, alternative drinking water sources and chlorination were organized to restrict the outbreaks and to clean the contaminated distribution network. This study highlights the emerging role of sapoviruses as a waterborne pathogen and warrants the need for testing of multiple viruses during outbreak investigation

Two Drinking Water Outbreaks Caused by Wastewater Intrusion Including Sapovirus in Finland

Drinking water outbreaks occur worldwide and may be caused by several factors, including raw water contamination, treatment deficiencies, and distribution network failure. This study describes two drinking water outbreaks in Finland in 2016 (outbreak I) and 2018 (outbreak II). Both outbreaks caused approximately 450 illness cases and were due to drinking water pipe breakage and subsequent wastewater intrusion into the distribution system. In both outbreaks, the sapovirus was found in patient samples as the main causative agent. In addition, adenoviruses and Dientamoeba fragilis (outbreak I), and noroviruses, astroviruses, enterotoxigenic and enterohemorragic Escherichia coli (ETEC and EHEC, respectively) and Plesiomonas shigelloides (outbreak II) were detected in patient samples. Water samples were analyzed for the selected pathogens largely based on the results of patient samples. In addition, traditional fecal indicator bacteria and host-specific microbial source tracking (MST) markers (GenBac3 and HF183) were analyzed from water. In drinking water, sapovirus and enteropathogenic E. coli (EPEC) were found in outbreak II. The MST markers proved useful in the detection of contamination and to ensure the success of contaminant removal from the water distribution system. As mitigation actions, boil water advisory, alternative drinking water sources and chlorination were organized to restrict the outbreaks and to clean the contaminated distribution network. This study highlights the emerging role of sapoviruses as a waterborne pathogen and warrants the need for testing of multiple viruses during outbreak investigation

Cut-off values to evaluate exercise-induced asthma in eucapnic voluntary hyperventilation test for children

Background and Aim The eucapnic voluntary hyperventilation (EVH) testing is a diagnostic tool for diagnostics of exercise-induced bronchoconstriction; while the testing has become more common among children, data on the test's feasibility among children remain limited. Our aim was to investigate EVH testing feasibility among children, diagnostic testing cut-off values, and which factors affect testing outcomes. Methods We recruited 134 patients aged 10-16 years with a history of exercise-induced dyspnoea and 100 healthy control children to undergo 6-min EVH testing. Testing feasibility was assessed by the children's ability to achieve >= 70% of the target minute ventilation of 30 times forced expiratory volume in 1 s (FEV1). Bronchoconstriction was assessed as a minimum of 8%, 10%, 12%, 15% or 20% fall in FEV1. Patient characteristics were correlated with EVH outcomes. Results Overall, 98% of the children reached >= 70%, 88% reached >= 80%, 79% reached >= 90% and 62% reached >= 100% of target ventilation in EVH testing; of children with a history of exercise-induced dyspnoea, the decline percentages were as follows: 24% (>= 8% fall), 17% (>= 10% fall), 10% (>= 12% fall), 6% (>= 15% fall) and 5% (>= 20% fall) in FEV1, compared to 11%, 4%, 3%, 1% and 0% among the healthy controls, respectively. Healthy controls and boys performed testing at higher ventilation rates (p < .05). Conclusion Eucapnic voluntary hyperventilation testing is feasible among children aged 10-16 years and has diagnostic value in evaluating exercise-induced dyspnoea among children. A minimum 10% fall in FEV1 is a good diagnostic cut-off value. Disease status appears to be important covariates

Emergence of unusual human rotavirus strains in Salento, Italy, during 2006–2007

<p>Abstract</p> <p>Background</p> <p>In recent years, rotavirus genotyping by RT-PCR has provided valuable information about the diversity of rotaviruses (RV) circulating throughout the world.</p> <p>The purpose of the present study was to monitor the prevalence of the different G and P genotypes of rotaviruses circulating in Salento and detect any uncommon or novel types.</p> <p>Methods</p> <p>During the period from January 2006 to December 2007, a total of 243 rotavirus positive stool samples were collected from children with diarrhoea admitted to four Hospitals in the province of Lecce (Copertino, Galatina, Gallipoli and Tricase).</p> <p>All the specimens were tested for RV by real time PCR and genotyped for VP7 (G-type) and VP4 (P-type) gene by reverse transcription (RT) and multiplex PCR using different type specific primers.</p> <p>Results</p> <p>In course of this study we identified 4 common G&P combinations viz. G2P[8], G1P[8], G2P[4] and G9P[8] amongst 59.8% of the typeable rotavirus positives.</p> <p>Rotavirus G2P[8] was recognized as the most widespread genotype during the sentinel-based survey in Salento.</p> <p>The detection of other novel and unusual strains, such as G2P[10], G4P[10], G8P[4], G9P[11] and G10P[8] is noteworthy.</p> <p>Furthermore, a significant number of mixed infections were observed during the survey period but G3P[8] rotaviruses were not detected.</p> <p>Conclusion</p> <p>This study highlights the genetic diversity among rotaviruses isolated from children in Salento and the emergence of some novel strains. Therefore, it is highly essential to continuously monitor for these strains so as to assess the impact of vaccines on RV strains circulating in Salento and understand the effect of strain variation on efficacy of presently available vaccines.</p

Priority setting of ICU resources in an influenza pandemic: a qualitative study of the Canadian public's perspectives

<p>Abstract</p> <p>Background</p> <p>Pandemic influenza may exacerbate existing scarcity of life-saving medical resources. As a result, decision-makers may be faced with making tough choices about who will receive care and who will have to wait or go without. Although previous studies have explored ethical issues in priority setting from the perspective of clinicians and policymakers, there has been little investigation into how the public views priority setting during a pandemic influenza, in particular related to intensive care resources.</p> <p>Methods</p> <p>To bridge this gap, we conducted three public town hall meetings across Canada to explore Canadian's perspectives on this ethical challenge. Town hall discussions group discussions were digitally recorded, transcribed, and analyzed using thematic analysis.</p> <p>Results</p> <p>Six interrelated themes emerged from the town hall discussions related to: ethical and empirical starting points for deliberation; criteria for setting priorities; pre-crisis planning; in-crisis decision-making; the need for public deliberation and input; and participants' deliberative struggle with the ethical issues.</p> <p>Conclusions</p> <p>Our findings underscore the importance of public consultation in pandemic planning for sustaining public trust in a public health emergency. Participants appreciated the empirical and ethical uncertainty of decision-making in an influenza pandemic and demonstrated nuanced ethical reasoning about priority setting of intensive care resources in an influenza pandemic. Policymakers may benefit from a better understanding the public's empirical and ethical 'starting points' in developing effective pandemic plans.</p

Epidemiological and virological investigation of a Norovirus outbreak in a resort in Puglia, Italy

<p>Abstract</p> <p>Background</p> <p>This paper describes the third large outbreak of Norovirus (NoV) gastroenteritis reported in the Southern Italy region of Puglia.</p> <p>Methods</p> <p>A matched case control study was conducted, on 19 July 2005, for investigating risk factors, using a structured questionnaire on food consumption. A multivariate analysis was conducted to estimate the adjusted Odds Ratios. Laboratory and environmental investigation were also performed.</p> <p>Results</p> <p>On the day of the study 41 cases were identified and 41 controls were enrolled. Controls were matched for age and gender. The mean age of the cases was 26 years old, and 58% were female. The clinical pattern of the disease was characterised by the presence of diarrhoea (95%), vomiting (70%), abdominal pain (51%) and fever (32%). Of the 41 cases included in the study, the majority (65%) were residents of Northern Italian regions. No food samples were available for testing. The matched univariate analysis revealed that cases were more likely to have consumed raw mussels, eggs or ice cubes made of tap water than controls. In the multivariate conditional logistic regression analysis, having eaten raw mussels or ice became more strongly associated with illness.</p> <p>All of the 20 faecal samples collected were tested for NoVs. Eighteen stools (90% of total examined) were positive by RT-PCR, and sequence analysis performed onto 3 samples confirmed the presence of a GGII NoV. No test specific for NoV was performed on water or food samples.</p> <p>Conclusion</p> <p>The most likely hypothesis supported by the findings of the epidemiological investigation was that illness was associated with raw mussels and ice, made with tap water. These hypothesis could not be confirmed by specific microbiologic testing for NoV in food or ice. The lack of clear knowledge of NoV as a major causative agent of epidemic outbreaks of gastroenteritis in Italy is due to the absence of timely reporting of the cases to the local public health offices and the uncommon practice of saving clinical samples for virological analysis after bacteriological testing.</p