94 research outputs found
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
946-103 Incremental Prognostic Power for Perioperative Cardiac Events of Clinical History and Semi·Quantitative Dobutamine Before Major Vascular Surgery
Using the presence of stress induced ischemia with dobutamine-atropine stress echocardiography (DSE) for predicting perioperative cardiac events (CE) in patients undergoing major vascular surgery has a high negative but low positive predictive value (PPV).Aim of the studyto improve the PPV of DSE by combining the value of clinical markers and DSE.Methodsin 300 consecutive patients clinical risk factors (diabetes, angina, Q waves on ECG, age>70 years, and history of ventricular arrhythmias) where assessed. DSE results were analyzed by quantifying the extent and severity of new wall motion abnormalities (NWMA) at peak stress. Also, heart rate threshold (HR-Thres) at which NWMA occurred was noted. Low HR-Thres was defined as NWMA at<70% of maximal age and sex related heart rate.Results27 CE occurred of which 5 cardiac deaths, 12 myocardial infarctions and 10 patients with unstable angina. One-hundred patients had no clinical risk factors, 200 one or more. All but 1 CE occurred in patients with 1 Or more risk factors. In 27 of 72 patients with a positive DSE a CE occurred (PPV 38%). Quantifying the extent and severity of NWMA at peak stress provided no additional information. The HR-Thres at which ischemia occurred improved PPV In 30 patients with a low HR-Thres, 20 CE occurred (PPV 67%). In the remaining 42 patients with a high HR-Thres, only 7 CE occurred (16%). The improvement of PPV from 38% to 67% is statistically highly significant (P < 0.01). All patients with a fatal CE and 8 of 12 patients with a myocardial infarction had a low HR-threshold.Conclusions1) in patients with no clinical risk factors additional stress testing is not efficient. 2) in patients with one or more risk factors semiquantitative DSE allows stratification of patients in low, intermediate, and high risk groups for CE
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
Improved cardiac risk stratification in major vascular surgery with dobutamine-atropine stress echocardiography
Objectives: This study sought to optimize preoperative cardiac risk stratification in a large group of consecutive candidates for vascular surgery by combining clinical risk assessment and semiquantitative dobutamine-atropine stress echocardiography. Background: Dobutamine-atropine stress echocardiography has been used for the prediction of perioperative cardiac risk in a small group of patients scheduled for elective major vascular surgery on the basis of the presence or absence of stress-induced regional left ventricular wall motion abnormalities. Methods: Clinical risk assessment and dobutamine-atropine stress echocardiography were performed in 302 consecutive patients presenting for major vascular surgery. The extent and severity of stress wall motion abnormalities and the heart rate at which they occurred, in addition to the presence of wall motion abnormalities at rest, were assessed. Results: The absence of clinical risk factors (angina, diabetes, Q waves on the electrocardiogram, symptomatic ventricular tachyarrhythmias, age >70 years) identified a low risk group of 100 patients with a 1% cardiac event rate (unstable angina). Dobutamine-atropine stress echocardiographic findings were positive in 72 patients. Twenty-seven patients had a perioperative cardiac event (cardiac death in 5, nonfatal infarction in 12, unstable angina pectoris in 10); all 27 patients had positive stress test results (positive predictive value 38%, negative predictive value 100%). The semiquantitative asse
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
Correlation between delayed-enhancement magnetic resonance and nitrate myocardial Tc-99m tetrofosmin scintigraphy in myocardial infarction: a case report
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
Basi di dati georeferenziati in ambiente GIS: esperienze di ricerca archeologica e topografica in siti magnogreci e siciliani
Presentazione di esperienze di implementazione di un sistema GIS per la gestione dei dati di scavo archeologico nei siti di Entella, Segesta e Kaulonia
Residui di ossido di etilene, etilen cloridrina, etilen glicole in soluzioni per uso oftalmico.
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