Hybrid modeling of a biorefinery separation process to monitor short-term and long-term membrane fouling

Membrane filtration is commonly used in biorefineries to separate cells from fermentation broths containing the desired products. However, membrane fouling can cause short-term process disruption and long-term membrane degradation. The evolution of membrane resistance over time can be monitored to track fouling, but this calls for adequate sensors in the plant. This requirement might not be fulfilled even in modern biorefineries, especially when multiple, tightly interconnected membrane modules are used. Therefore, characterization of fouling in industrial facilities remains a challenge. In this study, we propose a hybrid modeling strategy to characterize both reversible and irreversible fouling in multi-module biorefinery membrane separation systems. We couple a linear data-driven model, to provide high-frequency estimates of trans-membrane pressures from the available measurements, with a simple nonlinear knowledge-driven model, to compute the resistances of the individual membrane modules. We test the proposed strategy using real data from the world's first industrial biorefinery manufacturing 1,4-bio-butanediol via fermentation of renewable raw materials. We show how monitoring of individual resistances, even when done by simple visual inspection, offers valuable insight on the reversible and irreversible fouling state of the membranes. We also discuss the advantage of the proposed approach, over monitoring trans-membrane pressures and permeate fluxes, from the standpoints of data variability, effect of process changes, interaction between module in multi-module systems, and fouling dynamics

Microbiological quality of drinking water from dispensers in Italy

<p>Abstract</p> <p>Background</p> <p>Water coolers are popular in office buildings and commercial stores and the quality of this source of drinking water has the potential to cause waterborne outbreaks, especially in sensitive and immunocompromised subjects. The aim of this study was to determine the quality of water plumbed in coolers from commercial stores in comparison with tap water in Italy.</p> <p>Methods</p> <p>For each sample, microbial parameters and chemical indicators of contamination were evaluated and information about the date of installation, time since last ordinary and extraordinary maintenance of water coolers was collected.</p> <p>Results</p> <p>In all samples the chemical parameters (nitrite, ammonium, free active chlorine residual) did not exceed the reference values of the drinking water regulation; the pH value in 86.8% samples of the carbonated waters was lower than the reference limit. The microbiological results indicated that the bacteria count at 22°C and 37°C was higher than the required values in 71% and 81% for the non-carbonated water and in 86% and 88% for the carbonated one, respectively. <it>Enterococcus </it>spp. and <it>Escherichia coli </it>were not detected in any of the water samples. <it>Pseudomonas aeruginosa </it>was found in only one sample of the tap water and in 28.9% and 23.7% of the non-carbonated and carbonated water samples, respectively. No statistically significant differences in bacterial counts at 22°C and 37°C have been found between the non-carbonated and carbonated water from the sampled coolers in relation with the time since the last filter was substituted. The bacteriological quality of tap water was superior to that of non-carbonated and carbonated water from coolers.</p> <p>Conclusion</p> <p>The results emphasize the importance of adopting appropriate routinely monitoring system in order to prevent or to diminish the chances of contamination of this water source.</p

Seroprevalence of sars-cov-2 antibodies in adults and healthcare workers in southern italy

Background: This study was carried out to estimate the seroprevalence of SARS-CoV-2 antibodies in a Southern Italian population. Methods: The study was performed among students and workers of the University of Campania “Luigi Vanvitelli” and the relative Teaching Hospital. Participants were invited to undergo a blood sampling, an interview or to complete a self-administered questionnaire. Results: A total of 140 participants (5.8%) tested positive for SARS-CoV-2 antibodies. Positive SARS-CoV-2 test results increased significantly during the months of testing, and those who had had at least one symptom among fever, cough, dyspnea, loss of taste or smell and who had had contact with a family member/cohabitant with confirmed COVID-19 were more likely to test positive. Faculty members were less likely to have a positive test result compared to the healthcare workers (HCWs). Among HCWs, physicians showed the lowest rate of seroconversion (5.2%) compared to nurses (8.9%) and other categories (10%). Nurses and other HCWs compared to the physicians, those who had had at least one symptom among fever, cough, dyspnea, loss of taste or smell, and who had had contact with a family member/cohabitant with confirmed COVID-19 were more likely to test positive. Conclusions: The results have demonstrated that SARS-CoV-2 infection is rapidly spreading even in Southern Italy and confirm the substantial role of seroprevalence studies for the assessment of SARS-CoV-2 infection circulation and potential for further spreading

Dobutamine-atropine stress echocardiography and clinical data for predicting late cardiac events in patients with suspected coronary artery disease

purpose: To compare the relative value of clinical variables with dobutamine-atropine stress echocardiography to predict cardiac events during long-term follow-up. Dobutamine stress echocardiography is increasingly used for the detection of coronary artery disease, but little is known of its prognostic value. patients and methods: A total of 430 patients (310 men; mean age 61 years, range 22 to 90) were enrolled in the study. Patients were referred for chest pain complaints and were unable to perform an adequate exercise stress test. All patients underwent dobutamine-atropine stress test (incremental dobutamine infusion: 10 to 40 μ/kg/minute, continued with atropine 0.25 to 1 mg intravenously if necessary to achieve 85% of the age predicted maximal heart rate, without symptoms or signs of ischemia) and clinical cardiac evaluation. Follow-up was 17 ± 5 months, with a minimum of 6 months; 3 patients were lost to follow-up. Cardiac events were defined as cardiac death, nonfatal myocardial infarc

The CABB dataset: A multimodal corpus of communicative interactions for behavioural and neural analyses

We present a dataset of behavioural and fMRI observations acquired in the context of humans involved in multimodal referential communication. The dataset contains audio/video and motion-tracking recordings of face-to-face, task-based communicative interactions in Dutch, as well as behavioural and neural correlates of participants’ representations of dialogue referents. Seventy-one pairs of unacquainted participants performed two interleaved interactional tasks in which they described and located 16 novel geometrical objects (i.e., Fribbles) yielding spontaneous interactions of about one hour. We share high-quality video (from three cameras), audio (from head-mounted microphones), and motion-tracking (Kinect) data, as well as speech transcripts of the interactions. Before and after engaging in the face-to-face communicative interactions, participants’ individual representations of the 16 Fribbles were estimated. Behaviourally, participants provided a written description (one to three words) for each Fribble and positioned them along 29 independent conceptual dimensions (e.g., rounded, human, audible). Neurally, fMRI signal evoked by each Fribble was measured during a one-back working-memory task. To enable functional hyperalignment across participants, the dataset also includes fMRI measurements obtained during visual presentation of eight animated movies (35 minutes total). We present analyses for the various types of data demonstrating their quality and consistency with earlier research. Besides high-resolution multimodal interactional data, this dataset includes different correlates of communicative referents, obtained before and after face-to-face dialogue, allowing for novel investigations into the relation between communicative behaviours and the representational space shared by communicators. This unique combination of data can be used for research in neuroscience, psychology, linguistics, and beyond

Vaccination against hepatitis b virus: are Italian medical students sufficiently protected after the public vaccination programme?

The development of a vaccine against hepatitis B virus (HBV) has been a major achievement in terms of prevention of HBV infection. For the present study, we analysed the long-term immunogenicity and effectiveness of HBV vaccination among healthcare students with different working seniorities.Background: The development of a vaccine against hepatitis B virus (HBV) has been a major achievement in terms of prevention of HBV infection. For the present study, we analysed the long-term immunogenicity and effectiveness of HBV vaccination among healthcare students with different working seniorities. Methods: A cross-sectional study of undergraduate and postgraduate students attending the Medical School of the Second University of Naples was conducted between September 2012 and December 2014. HBV serum markers were determined and multivariate logistic regression analysis was used to identify factors associated with the level of long-term immunogenicity. Results: Of the 2,932 subjects evaluated, only 33 (1.1 %) declared no history of vaccination. All vaccinated subjects were HBsAg/anti-HBc negative, 459 of which had an anti-HBs titre <10 IU/L. The latter were younger, more likely to be attending a healthcare profession school (i.e., dental hygienists, nursing, paediatric nursing, radiography and midwifery) than a medical school (at either undergraduate or postgraduate level) and more likely to have been vaccinated in infancy. Conclusion: The results of this study suggest that assessment of HBV serum markers in workers potentially exposed to hospital infections is useful to identify small numbers of unvaccinated subjects or vaccinated subjects with low antibody titre, all of whom should be referred to a booster series of vaccinations

Digital design of new products: accounting for output correlation via a novel algebraic formulation of the latent-variable model inversion problem

Product design problems often require finding the raw materials and/or operating conditions (inputs) that are needed to achieve some pre-assigned quality specifications on the product (outputs). The problem can be tackled by first building a latent-variable model (e.g., partial least-squares regression) on historical manufacturing data of products similar to the new one, and then using model inversion to find the input conditions required to obtain the target product. However, in most practical cases, the variables characterizing product quality are correlated, and this may raise singularity issues upon algebraic model inversion. The most popular approach to cope with this relies on removing a priori some of the correlated quality variables from the model output matrix, and on building the latent-variable model in such a way that the inputs be related to the remaining outputs only. However, in this case the inputs obtained upon model inversion may not be able to ensure that the quality variables that were not included in the output matrix will be close enough to their targets. We propose a novel algebraic formulation of the latent-variable model inversion problem, named regularized direct inversion, which can cope with output correlation by design. The proposed formulation enables one to retain in the model output matrix all quality variables, and addresses output correlation by removing a posteriori only the non-systematic information that would cause singularity issues. Therefore, no structural information about the relation between inputs and out-puts is left out of the model by design, which in turn improves the performance of model inversion. The supe-riority of regularized direct inversion over the standard approach, and its ability to cope with model uncertainty, are proved using two simulated batch processes: a generic fermentation process, and a process for the manufacturing of penicillin

Studio sulla prevalenza del consumo di psicofarmaci in un campione di popolazione napoletana.

Studio sul consumo di psicofarmaci in un campione di popolazione napoletan