671 research outputs found

    molecular enrichment for detection of s aureus in recreational waters

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    The identification of rapid methods for the control of recreational water and of aquatic environments with similar characteristics is necessary to provide adequate levels of health safety for users. Molecular techniques have been proposed in recent years as a viable alternative to traditional microbiological methods, as they offer various advantages and are less time consuming than traditional tests. An innovative protocol based on molecular enrichment that allows the identification of low concentrations of Staphylococcus aureus in recreational water has been developed. The method is based on the specific amplification of prokaryotic genomic DNA by the usage of universal primers for 23S rDNA; subsequently, a second amplification step is performed with specific real-time polymerase chain reaction (PCR) primers and probe. This approach shows sensitivity levels similar to those observed with microbiological tests, with the additional benefits of the specificity typical of nucleic acids techniques. This methodology is easily applicable also to other microbiological parameters, representing an important milestone in hygiene monitoring by the detection of specific pollution indicators

    Regulations concerning natural swimming ponds in Europe: considerations on public health issues

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    Natural swimming ponds (NSPs) are a new type of recreational water facility characterized by the substitution of traditional disinfection with biodepuration. While this feature meets esthetic desires of users, specific concerns on public health issues have been raised by the scientific community and local authorities. The absence of a European directive applicable to these environments leaves each country without specific and harmonized indications. The present work describes the local/national policy situation, describing adopted parameters and monitoring activities. All documents underline the need for appropriate microbiological analysis and correct water management

    Italian cardiovascular mortality charts of the CUORE Project: are they comparable with the SCORE charts?

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    Background The aim of this study was to build risk charts for the assessment of cardiovascular mortality of the CUORE project, an Italian longitudinal study, and to compare them with the systematic coronary risk evaluation (SCORE) project charts for low risk European countries. Design Random population samples enrolled in the 1980s and 1990s in Italy were included in the analysis: 7520 men and 13 127 women aged 35-69 years without previous cardiovascular events and with a mean follow-up period of 10 years for cardiovascular disease. ICD-9 codes of death certificates similar to those of the SCORE project were considered when they appear as first cause of death. Methods Sex-stratified Cox proportional hazard model including age, systolic blood pressure, ratio between total and HDL cholesterol, and smoking habit as risk factors was used to assess cardiovascular mortality. Results Analysis showed that all risk factors included in the model were statistically significant. The corresponding area under the receiver operating characteristic curve was 0.825 (95% confidence interval: 0.803-0.846) for men and 0.850 (0.823-0.877) for women. The CUORE project charts yielded similar results to the corresponding charts of the SCORE project: Lin's coefficient was 0.929 for men and 0.935 for women. Conclusion The comparison between CUORE and SCORE mortality risk charts shows that SCORE charts reflect quite well the Italian cardiovascular mortality and, correspondingly, Italian cohorts of the CUORE project are quite representative of European countries at low risk for cardiovascular mortality

    Syntrophy drives the microbial electrochemical oxidation of toluene in a continuous-flow "bioelectric well"

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    Microbial electrochemical technologies (MET) are promising for the remediation of groundwater pollutants such as petroleum hydrocarbons (PH). Indeed, MET can provide virtually inexhaustible electron donors or acceptors directly in the subsurface environment. However, the degradation mechanisms linking contaminants removal to electric current flow are still largely unknown, hindering the development of robust design criteria. Here, we analysed the degradation of toluene, a model PH, in a bioelectrochemical reactor known as "bioelectric well"operated in continuous-flow mode at various influent toluene concentrations. With increasing concentration of toluene, the removal rate increased while the current tended to a plateau, hence the columbic efficiency decreased. Operation at open circuit confirmed that the bioelectrochemical degradation of toluene proceeded via a syntrophic pathway involving cooperation between different microbial populations. First of all, hydrocarbon degraders quickly converted toluene into metabolic intermediates probably by breaking the aromatic ring upon fumarate addition. Subsequently, fermentative bacteria converted these intermediates into volatile fatty acids (VFA) and likely also H2, which were then used as substrates by electroactive microorganisms forming the anodic biofilm. As toluene degradation is faster than subsequent conversion steps, the increase in intermediate concentration could not result in a current increase. This work provides valuable insights on the syntrophic degradation of BTEX, which are essential for the application of microbial electrochemical system to groundwater remediation of petroleum hydrocarbons

    An international comparative study of blood pressure in populations of European vs. African descent

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    Background: The consistent finding of higher prevalence of hypertension in US blacks compared to whites has led to speculation that African-origin populations are particularly susceptible to this condition. Large surveys now provide new information on this issue. Methods: Using a standardized analysis strategy we examined prevalence estimates for 8 white and 3 black populations (N = 85,000 participants). Results: The range in hypertension prevalence was from 27 to 55% for whites and 14 to 44% for blacks. Conclusions: These data demonstrate that not only is there a wide variation in hypertension prevalence among both racial groups, the rates among blacks are not unusually high when viewed internationally. These data suggest that the impact of environmental factors among both populations may have been under-appreciated

    Mini-invasive robotic assisted pyelolithotomy: Comparison between the transperitoneal and retroperitoneal approach.

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    OBJECTIVE: To compare the retroperitoneal with the transperitoneal approach in a series of patients underwent to robotic-assisted pyelolithotomy (RP). MATERIALS AND METHODS: From January 2015 to December 2018 we evaluated 20 patients subjected to robotic pyelolithotomy; 11 patients were treated with retroperitoneal approach (RRP) and 9 with transperitoneal approach (TRP). For each patient intra and perioperative data were recorded: operative time (OT), blood loss (BL), length of hospital stay (LOS), stone clearance, post-operative complications and time to remove the drain. The presence of stone fragments < 4 mm was considered as stone free rate. RESULTS: The principal stone burden was greater in the TRP group than in the RRP group (48 ± 10 mm vs 32 ± 14 mm, p = 0.12). Preoperative hydronephrosis was present in 7 (64%) patients in RRP group and a mild hydronephrosis in 3 of TRP group (p = 0.04). The average operative time was higher in the RRP group than in the TRP group (203 ± 45 min vs 137 ± 31 min, p = 0.002). The average blood loss was 305 ± 175 ml in the RRP group versus 94 ± 104 ml in the TRP group (p = 0.005). The stone free rate was similar between the two groups, 36% (4 patients) in the RRP group and 44% (4 patients) in the TRP (p = 0.966). CONCLUSIONS: RP appears to be a safe and effective minimally invasive treatment for some patients with renal staghorn calculi or urinary tract malformations. The TRP may give lower operative time and better results in terms of blood loss and length of hospital stay

    Noise control in enclosures: Modeling and experiments with T-shaped acoustic resonators

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    This paper presents a theoretical and experimental study of noise control in enclosures using a T-shaped acoustic resonator array. A general model with multiple resonators is developed to predict the acoustic performance of small resonators placed in an acoustic enclosure. Analytical solutions for the sound pressure inside the enclosure and the volume velocity source strength out of the resonator aperture are derived when a single resonator is installed, which provides insight into the physics of acoustic interaction between the enclosure and the resonator. Based on the understanding of the coupling between the individual resonators and enclosure modes, both targeted and nontargeted, a sequential design methodology is proposed for noise control in the enclosure using an array of acoustic resonators. Design examples are given to illustrate the control performance at a specific or at several resonance peaks within a frequency band of interest. Experiments are conducted to systematically validate the theory and the design method. The agreement between the theoretical and experimental results shows that, with the help of the presented theory and design methodology, either single or multiple resonance peaks of the enclosure can be successfully controlled using an optimally located acoustic resonator array. © 2007 Acoustical Society of America
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