39 research outputs found
Early Warning and Conflict Prevention in the Euro-Med Area. A Research Report by the Istituto Affari Internazionali
No full textModeling Realistic Geometries in Human Intrathoracic Airways
No full textGeometrical models of the airways offer a comprehensive perspective on the complex interplay between lung structure and function. Originating from mathematical frameworks, these models have evolved to include detailed lung imagery, a crucial enhancement that aids in the early detection of morphological changes in the airways, which are often the first indicators of diseases. The accurate representation of airway geometry is crucial in research areas such as biomechanical modeling, acoustics, and particle deposition prediction. This review chronicles the evolution of these models, from their inception in the 1960s based on ideal mathematical constructs, to the introduction of advanced imaging techniques like computerized tomography (CT) and, to a lesser degree, magnetic resonance imaging (MRI). The advent of these techniques, coupled with the surge in data processing capabilities, has revolutionized the anatomical modeling of the bronchial tree. The limitations and challenges in both mathematical and image-based modeling are discussed, along with their applications. The foundation of image-based modeling is discussed, and recent segmentation strategies from CT and MRI scans and their clinical implications are also examined. By providing a chronological review of these models, this work offers insights into the evolution and potential future of airway geometry modeling, setting the stage for advancements in diagnosing and treating lung diseases. This review offers a novel perspective by highlighting how advancements in imaging techniques and data processing capabilities have significantly enhanced the accuracy and applicability of airway geometry models in both clinical and research settings. These advancements provide unique opportunities for developing patient-specific models
Sex Differences in the Anatomy of the Airways and the Lungs: Impact on Dysanapsis across the Lifespan
No full textComputational Fluid Dynamics (CFD) Analysis of Subject-specific Bronchial Tree Models in Lung Cancer Patients
No full textLung resection is the only potentially curative treatment for lung cancer. The inevitable partial removal of functional lung tissue along with the tumoral mass requires a careful and structured pre-operative condition of patients. In particular, the postoperative residual functionality of the lung needs to be predicted. Clinically, this is assessed through algorithms based on pulmonary function tests (PFTs). However, these approaches neglect the local airway segment's functionality and provide a globally averaged evaluation. CFD was demonstrated to provide patient-specific, quantitative, and local information on flow dynamics and regional ventilation in the bronchial tree. This study aims to apply CFD to characterize the flow dynamics in 12 patients affected by lung cancer and evaluate the effects of the tumoral masses on flow parameters and lobar flow distribution. Patient-specific airway models were reconstructed from CT images, and the tumoral masses were manually segmented. Measurements of lungs and tumor volumes were collected. A peripherality index was defined to describe tumor distance from the parenchyma. CFD simulations were performed in Fluent®, and the results were analyzed in terms of flow parameters and lobar volume flow rate (VFR). The predicted postoperative forced expiratory volume in 1s (ppoFEV1) was estimated and compared to the current clinical algorithm. The patients under analysis showed relatively small tumoral masses located close to the lung parenchyma. CFD results did not highlight lobar alterations of flow parameters, whereas the flow to the lung affected by the tumor was found to be significantly lower (p=0.026) than the contralateral lung. The estimation ppoFEV1 obtained through the results of the simulations showed a high correlation (ρ=0.993, p<0.001) with the clinical formula.Clinical Relevance- The proposed study establishes the efficacy and applicability of CFD for the pre-operative characterization of patients undergoing lobectomy surgery. This technique can provide additional information on local functionality and flow dynamics to support patients' operability
Evaluation of Ultrasound Measurement of Subcutaneous Fat Thickness in Dairy Jennies during the Periparturient Period
No full textThe body condition score (BCS) represents a practical but subjective method for assessing body fat reserves. Real time ultrasonography (RTU) has been proposed as an accurate method to objectively measure subcutaneous fat (SF) thickness and predict body fat reserves in cows, horses and donkeys. The aim of the present study was to describe RTU measures of SF thickness during periparturient period in jennies. The present prospective cohort study evaluated six dairy jennies. SF RTU were performed at 15 and 7 days before the presumptive delivery, and 2, 15 and 30 days after delivery. A portable ultrasound machine and multifrequency linear transducer (5–7.5 MHz) was used. RTU images were obtained in six sites (S1–S6). Results at each time point were reported as mean ± standard deviation and compared through time. A total of 180 images were evaluated. RTU technique was easy to perform and well tolerated. No statistically significant differences were found of each site during time, except for S2 and S6a: S2 at T2 and S6a at T1 were significatively different to values obtained at T5. The RTU mean values were above those reported by others, suggesting major physio-logical challenges related to energy balance and fat mobilization in pregnant jennies bred for milking production. BCS and sites through observational time have shown a good and reliable association. Our study could give preliminary indications on fat reserves in different body locations evaluated thanks to RTU and it show no significative variation of SF thickness, in pregnant and lactating jennies
Analytical protocols for the determination of sulphur compounds characteristic of the metabolism of Chlorobium limicola
No full textAbstractChlorobium limicola belongs to the green sulphur bacteria that has a potential for technological applications such as biogas clean up oxidising hydrogen sulphide to elemental sulphur through photosynthetic process. In the present work, analytical methods are described for the determination of different sulphur species in C. limicola cultures – sulphide by GC-FPD, sulphate by ionic HPLC and elemental sulphur by RP HPLC. The latter method eliminates the need for chloroform extraction of water suspensions of elemental sulphur. Data from sulphide and elemental sulphur analyses have been compared with ones coming from more traditional analytical methodologies
Computational fluid dynamics of the airways after left-upper pulmonary lobectomy: A case study
No full textPulmonary lobectomy is the gold standard intervention for lung cancer removal and consists of the complete resection of the affected lung lobe, which, coupled with the re-adaptation of the remaining thoracic structures, decreases the postoperative pulmonary function of the patient. Current clinical practice, based on spirometry and cardiopulmonary exercise tests, does not consider local changes, providing an average at-the-mouth estimation of residual functionality. Computational Fluid Dynamics (CFD) has proved a valuable solution to obtain quantitative and local information about airways airflow dynamics. A CFD investigation was performed on the airway tree of a left-upper pulmonary lobectomy patient, to quantify the effects of the postoperative alterations. The patient-specific bronchial models were reconstructed from pre- and postoperative CT scans. A parametric laryngeal model was merged to the geometries to account for physiological-like inlet conditions. Numerical simulations were performed in Fluent. The postoperative configuration revealed fluid dynamic variations in terms of global velocity (+23%), wall pressure (+48%), and wall shear stress (+39%). Local flow disturbances emerged at the resection site: a high-velocity peak of 4.92 m/s was found at the left-lower lobe entrance, with a local increase of pressure at the suture zone (18 Pa). The magnitude of pressure and secondary flows increased in the trachea and flow dynamics variations were observed also in the contralateral lung, causing altered lobar ventilation. The results confirmed that CFD is a patient-specific approach for a quantitative evaluation of fluid dynamics parameters and local ventilation providing additional information with respect to current clinical approaches
A novel photobioreactor system for hydrogen sulphide biogas clean-up
No full textHydrogen sulphide (H2S) is a toxic and corrosive gas. Its removal from biogas is important to obtain valuable biomethane. A novel photobioreactor (PBR) has been conceived where the bacterium Chlorobium limicola converts H2S in elemental sulphur through an anoxigenic photosynthetic process. This system has proven to be stable over time. Quantitative clean-up was achieved in tests with artificial biogas with high concentration of H2S. Molecular analysis was used to check the stability of the culture under non-sterile conditions. This analysis has shown the presence of a strain belonging to Epsilonproteobacteria that does not affect the efficiency of the process. An aliquot of this bacterial culture was sampled and used as inoculum in a second experiment where the PBR was installed downstream of an anaerobic digestion plant. The efficiency of H2S removal was around 90% and the bacterial consortium remained stable. Copyright © 2017 Inderscience Enterprises Ltd
Ultrasonographic Appearance of Elbow Joints in a Population of Amiata Donkeys
No full textUltrasound (US) is a well-established technique for investigating joint diseases in horses, complementary to radiography. Few studies have been performed on the ultrasonographic aspect of the elbow joint in horses and no reports are available on donkeys. The aim of this study is to describe the ultrasonographic appearance of the elbow joint in healthy donkeys. Descriptive cohort study included 34 elbow joints, which were evaluated in 17 donkeys. Inclusion criteria included no lameness or musculoskeletal diseases in the donkeys. The structures evaluated were the lateral and medial collateral ligaments, ulnaris lateralis proximal tendon, distal biceps brachii tendon, triceps brachii tendon, and the articular space. For each structure, one good-quality image was recorded. The structures were retrospectively assessed for echogenicity, fiber orientation, bone appearance, and shape. The prevalence of the visualized structures was calculated. Cohen κ coefficient was calculated for the repeatability (intraoperator agreement), the reproducibility (interoperator agreement), and the influence of the operator's experience in US examination. The US appearance of the structures was described. Statistical analysis showed scarce-to-moderate agreement concerning the repeatability and mostly scarce-to-good agreement concerning the reproducibility of the US examination; finally, low-to-discrete agreement concerning the operator's experience. Technical difficulties precluded an accurate description of the medial collateral ligament. The healthy animals included were limited. The US examination of the elbow joint in donkeys were similar to the features reported in horses. Individual experience partially influences the execution and the assessment of the US images
