Anaerobic digestion of screenings for biogas recovery

Screenings comprise untreatable solid materials that have found their way into the sewer. They are removed during preliminary treatment at the inlet work of any wastewater treatment process using a unit operation termed as a screen and at present are disposed of to landfill. These materials, if not removed, will damage mechanical equipment due to its heterogeneity and reduce overall treatment process, reliability and effectiveness. That is why this material is retained and prevented from entering the treatment system before finally being disposed of. The amount of biodegradable organic matter in screenings often exceeds the upper limit and emits a significant amount of greenhouse gases during biodegradation on landfill. Nutrient release can cause a serious problem of eutrophication phenomena in receiving waters and a deterioration of water quality. Disposal of screenings on landfill also can cause odour problem due to putrescible nature of some of the solid material. In view of the high organic content of screenings, anaerobic digestion method may not only offer the potential for energy recovery but also nutrient. In this study, the anaerobic digestion was performed for 30,days, at controlled pH and temperature, using different dry solids concentrations of screenings to study the potential of biogas recovery in the form of methane. It was found screenings have physical characteristics of 30% total solids and 93% volatile solids, suggesting screenings are a type of waste with high dry solids and organic contents. Consistent pH around pH 6.22 indicates anaerobic digestion of screenings needs minimum pH correction. The biomethane potential tests demonstrated screenings were amenable to anaerobic digestion with methane yield of 355,m3/kg VS, which is comparable to the previous results. This study shows that anaerobic digestion is not only beneficial for waste treatment but also to turn waste into useful resources

Adherence issues related to sublingual immunotherapy as perceived by allergists

Objectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers. © 2010 Scurati et al, publisher and licensee Dove Medical Press Ltd

Epistatic Roles for Pseudomonas aeruginosa MutS and DinB (DNA Pol IV) in Coping with Reactive Oxygen Species-Induced DNA Damage

Pseudomonas aeruginosa is especially adept at colonizing the airways of individuals afflicted with the autosomal recessive disease cystic fibrosis (CF). CF patients suffer from chronic airway inflammation, which contributes to lung deterioration. Once established in the airways, P. aeruginosa continuously adapts to the changing environment, in part through acquisition of beneficial mutations via a process termed pathoadaptation. MutS and DinB are proposed to play opposing roles in P. aeruginosa pathoadaptation: MutS acts in replication-coupled mismatch repair, which acts to limit spontaneous mutations; in contrast, DinB (DNA polymerase IV) catalyzes error-prone bypass of DNA lesions, contributing to mutations. As part of an ongoing effort to understand mechanisms underlying P. aeruginosa pathoadaptation, we characterized hydrogen peroxide (H2O2)-induced phenotypes of isogenic P. aeruginosa strains bearing different combinations of mutS and dinB alleles. Our results demonstrate an unexpected epistatic relationship between mutS and dinB with respect to H2O2-induced cell killing involving error-prone repair and/or tolerance of oxidized DNA lesions. In striking contrast to these error-prone roles, both MutS and DinB played largely accurate roles in coping with DNA lesions induced by ultraviolet light, mitomycin C, or 4-nitroquinilone 1-oxide. Models discussing roles for MutS and DinB functionality in DNA damage-induced mutagenesis, particularly during CF airway colonization and subsequent P. aeruginosa pathoadaptation are discussed

Dilatative percutaneous tracheostomy during double antiplatelet therapy: two consecutive cases.

This article reports two cases of dilatative percutaneous tracheostomy performed on patients treated with double antiplatelet therapy. Both patients had cardiac arrest following myocardial infarction. After primary angioplasty with stent placement, a double antiplatelet therapy was started. Due to poor neurological outcome, dilatative percutaneous tracheostomy was performed on both patients. Antiplatelet therapy was not discontinued because of the unacceptable risk of stent thrombosis. No immediate or late hemorrhagic complications occurred. In our experience, dilatative percutaneous tracheostomy during double antiplatelet therapy can be safely performed in selected patients without other risk factors

Invasive fungal infections in the intensive care unit: a multicentre, prospective, observational study in Italy (2006-2008)

Critically ill patients admitted to intensive care units (ICU) are highly susceptible to healthcare-associated infections caused by fungi. A prospective sequential survey of invasive fungal infections was conducted from May 2006 to April 2008 in 38 ICUs of 27 Italian hospitals. A total of 384 fungal infections (318 invasive Candida infections, three cryptococcosis and 63 mould infections) were notified. The median rate of candidaemia was 10.08 per 1000 admissions. In 15% of cases, the infection was already present at the time of admission to ICU. Seventy-seven percent of Candida infections were diagnosed in surgical patients. Candida albicans was isolated in 60% of cases, Candida glabrata and Candida parapsilosis in 13%, each. Candida glabrata had the highest crude mortality rate (60%). Aspergillus infection was diagnosed in 32 medical and 25 surgical patients. The median rate was 6.31 per 1000 admissions. Corticosteroid treatment was the major host factor. Aspergillosis was demonstrated to be more severe than candidiasis as the crude mortality rate was significantly higher (63% vs. 46%), given an equal index of severity, Simplified Acute Physiology Score (SAPS-II). The present large nationwide survey points out the considerable morbidity and mortality of invasive fungal infections in surgical as well as medical patients in ICU