Experimental and Theoretical Investigation of Vibro-Impact Motions of a Gear Pair Subjected to Torque Fluctuations to Define a Rattle Noise Severity Index

Vibro-impacts are common in various automotive engine and transmission gear applications. They are known to cause excessive noise levels, often called rattling or hammering. Input and output fluctuations acting on such systems cause tooth separations and sequences of impacts allowed by backlash at the gear mesh interfaces. The fluctuations leading gear rattling have often been studied for specific applications with the excitations produced typically by an internal combustion engine. As such, rattle evaluations have been often empirical and specific to the systems considered. In this study, an experimental test set-up of a gear pair is developed to emulate the same torque fluctuations in a laboratory environment. This set-up is used to establish an impact velocity-based rattle severity index defined by the measured torsional behavior of the drive train that is shown to correlate well with the measured sound pressure levels. With that, a validated dynamic model of the experimental setup is employed to predict the same index to allow estimation of rattle noise outcome solely from a torsional dynamic model of the drivetrain. Predicted rattle severity indexes are shown to agree well with the measured ones within wide ranges of torque fluctuations and backlash magnitudes, allowing an assessment of rattle performance of a drivetrain solely from a torsional model.

A new tool for assessing Pectus Excavatum by a semi-automatic image processing pipeline calculating the classical severity indexes and a new marker: the Volumetric Correction Index

Background In clinical assessment of Pectus Excavatum (PE), the indication to surgery is based not only on symptoms but also on quantitative markers calculated from Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scans. According to clinical routine, these indexes are measured manually by radiologists with limited computer support. This process is time consuming and potentially subjected to inaccuracy and individual variability in measurements. Moreover, the existing indexes have limitations, since they are based on linear measurements performed on single slices rather than on volumetric data derived from all the thoracic scans. Results In this paper we present an image processing pipeline aimed at providing radiologists with a computer-aid tool in support of diagnosis of PE patients developed in MATLAB® and conceived for MRI images. This framework has a dual purpose: (i) to automatize computation of clinical indexes with a view to ease and standardize pre-operative evaluation; (ii) to propose a new marker of pathological severity based on volumetric analysis and overcoming the limitations of existing axial slice-based indexes. Final designed framework is semi-automatic, requiring some user interventions at crucial steps: this is realized through a Graphical User Interface (GUI) that simplifies the interaction between the user and the tools. We tested our pipeline on 50 pediatric patients from Gaslini Children’s Hospital and performed manual computation of indexes, comparing the results between the proposed tool and gold-standard clinical practice. Automatic indexes provided by our algorithm have shown good agreement with manual measurements by two independent readers. Moreover, the new proposed Volumetric Correction Index (VCI) has exhibited good correlation with standardized markers of pathological severity, proving to be a potential innovative tool for diagnosis, treatment, and follow-up. Conclusions Our pipeline represents an innovative image processing in PE evaluation, based on MRI images (radiation-free) and providing the clinician with a quick and accurate tool for automatically calculating the classical PE severity indexes and a new more comprehensive marker: the Volumetric Correction Index.

Impact of plasma 5-hydroxyindoleacetic acid, a serotonin metabolite, on clinical outcome in septic shock, and its effect on vascular permeability

Septic shock is characterized by dysregulated vascular permeability. We hypothesized that the vascular permeability of endothelial cells (ECs) would be regulated by serotonin via serotonin-Rho-associated kinase (ROCK) signaling. We aimed to determine the impact of 5-hydroxyindoleacetic acid (5-HIAA) on septic shock as a novel biomarker. Plasma 5-HIAA levels and disease severity indices were obtained from 47 patients with sepsis. The association between 5-HIAA levels and severity indices was analyzed. Permeability upon serotonin stimulation was determined using human pulmonary microvascular ECs. 5-HIAA were significantly higher in septic shock patients than in patients without shock or healthy controls (p = 0.004). These elevated levels were correlated with severity indexes (SOFA score [p < 0.001], APACHE II [p < 0.001], and PaO2:FiO2 [p = 0.02]), and longitudinally associated with worse clinical outcomes (mechanical ventilation duration [p = 0.009] and ICU duration [p = 0.01]). In the experiment, serotonin increased the permeability of ECs, which was inhibited by the ROCK inhibitor (p < 0.001). Serotonin increases vascular permeability of ECs via ROCK signaling. This suggests a novel mechanism by which serotonin disrupts endothelial barriers via ROCK signaling and causes the pathogenesis of septic shock with a vascular leak. Serotonin serves as a novel biomarker of vascular permeability.

THE EFFECT OF HYDROTHERMAL PRETREATMENT ON THE ANAEROBIC DIGESTION OF THICKENED WASTE ACTIVATED SLUDGE AND SOURCE SEPARATED ORGANICS

The objective of this study was to evaluate the impact of hydrothermal pretreatment of source separated organics (SSO) and thickened waste activated sludge (TWAS) on the solubilization and biomethane production. The feedstocks went through 15 different conditions in a wide range of temperature (150-240°C), retention time (5-30) min and severity indexes (3-5). The result of the study revealed that the effect of hydrothermal pretreatment can vary based on the feedstock primary properties and the optimum pretreatment condition. In this study, the optimum pretreatment conditions for highest solubilization and solid reduction of the SSO were 220°C and 10 minutes retention time, however, for highest methane production, it was 190°C for 20 minutes. In case of TWAS, the result revealed that the maximum biomethane production was achieved at pretreatment conditions of 160°C and 20 min, while, the highest solubilization and solid reduction was observed in 220°C and 10 minutes retention time.

THE EFFECT OF HYDROTHERMAL PRETREATMENT ON THE ANAEROBIC DIGESTION OF THICKENED WASTE ACTIVATED SLUDGE AND SOURCE SEPARATED ORGANICS

The objective of this study was to evaluate the impact of hydrothermal pretreatment of source separated organics (SSO) and thickened waste activated sludge (TWAS) on the solubilization and biomethane production. The feedstocks went through 15 different conditions in a wide range of temperature (150-240°C), retention time (5-30) min and severity indexes (3-5). The result of the study revealed that the effect of hydrothermal pretreatment can vary based on the feedstock primary properties and the optimum pretreatment condition. In this study, the optimum pretreatment conditions for highest solubilization and solid reduction of the SSO were 220°C and 10 minutes retention time, however, for highest methane production, it was 190°C for 20 minutes. In case of TWAS, the result revealed that the maximum biomethane production was achieved at pretreatment conditions of 160°C and 20 min, while, the highest solubilization and solid reduction was observed in 220°C and 10 minutes retention time.

Syncope in relation to pulmonary arterial obstructive burden, hemodynamic status and short- and long-term outcome in patients with acute pulmonary embolism

Background and aims Although syncope (S) has been reported as one of the presenting findings in patients (pts) with acute pulmonary embolism (APE), its clinical and haemodynamic correlates and impacts on the long-term outcome in this setting remains to be determined. In this single-centre study we evaluated the clinical and haemodynamic significance of S in APE in initial asessment, and during short- and long-term follow-up period. Methods Our study was based on the retrospective and prospective analysis of the overall 641 pts (age 65 (51–74 IQR) yrs, 56.2% female) with diagnosis of documented APE who underwent anticoagulant (n=207), thrombolytic (n=164), utrasound-facilitated thrombolysis (UFT) (n=218) or rheolytic thrombectomy (RT) (n=52). The systematic work- up including multidetector computed tomography (MDCT), Echo, biomarkers, and PE severity indexes were performed in all pts, and Qanadli score (QS) was used as the measure of the thrombotic burden in the pulmonary arteries (PA). Results The S as the presenting symptom In 30.2% of pts with APE. At baseline assessment, S(+) vs S(−) APE subgroups had a significantly shorter symptom-diagnosis interval, a higher risk status according to the significant elevations in troponin T, D-dimer, the higher PE severity indexes, a more deteriorated right ventricle/left ventricle ratio (RV/LV r), right atrial/left atrial ratio (LA/RAr) and RV longitudinal function indexes including tricuspid annular planary excursion (TAPSE) and tissue velocity (St), a significantly higher PA obstructive burden as assessed by QS and PA pressures. Thrombolytic therapy (36.2% vs 21%, p&lt;0.001) and RT (11.9% vs 6.47%, p=0.037) were more frequently utilized S(+) as compared to S(−) group. However, all these differences between two subgroups were found to disappear after evidence-based APE treatments. In-hospital mortality (IHM) (12.95% vs 6%, p=0.007) and minor bleeding (10.36% vs 2.9%, p&lt;0.001) were significantly higher in S(+) pts as compared to those in S(−) subgroup. Binominal logistic regression analysis revealed that PESI score and RV/LVr independently associated with S while IHM was only predicted by age and heart rate. The COX proportional hazard method showed that RV/LVr at discharge and malignancy were independently associated with cumulative mortality during follow-up duration of 620 (200–1170 IQ) days. Conclusions The presence of S in pts with APE was found to be asociated with a higher PA obstructive burden, a more deteriorated RV function and haemodynamics and higher risk status which may need more agressive reperfusion treatments. However, in the presence of the optimal treatments, S did not predict neither in-hospital outcome, nor long-term mortality. Funding Acknowledgement Type of funding source: None

Correlation between Clinical Symptoms and Lab Tests with Endoscopic Severity Indexes in Patients with Inflammatory Bowel Diseases

BACKGROUND The Crohn’s Disease Endoscopic Index of Severity (CDEIS) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) are two validated endoscopic scoring system to evaluate patients with inflammatory bowel diseases (IBD). We conducted this study to evaluate the correlation between clinical symptoms and lab tests with these indexes in patients with Crohn’s disease (CD) and ulcerative colitis (UC). METHODS In this analytical study, 373 consecutive patients referred to Shahid Mohammadi Hospital with IBD were enrolled. All patients underwent complete ileocolonoscopy, and the endoscopic severity indexes (CDEIS and UCEIS) were calculated, and their relation with clinical symptoms and lab tests was evaluated. RESULTS Fever observed only in six patients (1.6%). It was associated with significantly higher CDEIS and UCEIS (p = 0.02 and p < 0.001, respectively). Also, diarrhea was correlated with significantly higher UCEIS (p < 0.001). The mean fecal calprotectin was 647.64 ± 409.37 µg/g in CD and 567.30 ± 342.49 µg/g in UC patients. Higher calprotectin level was observed in patients with higher CRP level (p = 0.001), erythrocyte sedimentation rate (ESR) level, CDEIS, and UCEIS (r = 0.438; 0.473; and 0.517; respectively, all with p < 0.001). CONCLUSION Our study showed that although fever and diarrhea are associated with higher endoscopic severity scores in patients with IBD, no clinical symptom could reliably predict the endoscopic results, alone. Furthermore, higher fecal calprotectin level is associated with higher ESR and C reactive protein levels, CDEIS, and UCEIS.

Galectin-3: A Potential Biomarker of Rheumatic Diseases

Background: The purpose of our study was to assess the serum galectin-3 level and its potential association with disease activity and severity indexes in patients with rheumatic diseases.Methods: Eighty-two patients with rheumatoid arthritis (RA), 49 patients with systemic sclerosis (SSc), and 18 patients with systemic lupus erythematosus (SLE) were enrolled in this study. The control group comprised 30 healthy controls. Galectin-3 concentration in serum was measured using immunochemical method. Results: The galectin-3 concentration were significantly elevated in the RA, SSc and SLE in comparison to the control group (P=0.000, P=0.000, P<0.001; respectively). But there were no significant differences in the serum galectin-3 levels between rheumatic diseases (H=0.395, P=0.821). In RA and SSc patients, galectin-3 positively correlated with erythrocyte sedimentation rate (R=0.332, P=0.004; R=0.384, P=0.009; respectively). The diagnostic accuracy (ACC) of galectin-3 was high in all rheumatic diseases (87.5% for RA, 83.1% for SSc, 81.1% for SLE). ROC analysis revealed that galectin-3 had an excellent diagnostic power in RA (AUC=0.911) and SSc (AUC=0.903) and very good for SLE (AUC=0.859).Conclusions: We concluded that serum galectin-3 due to the high diagnostic power can be a very good laboratory marker in RA and SSc patients and a useful tool in the diagnosis of SLE.