226 research outputs found
3D numerical simulation of hydro-acoustic waves registered during the 2012 negros-cebu earthquake
The paper investigates on the hydro-acoustic waves propagation caused by the underwater earthquake, occurred on 6 February 2012, between the Negros and Cebu islands, in the Philippines. Hydro-acoustic waves are pressure waves that propagate at the sound celerity in water. These waves can be triggered by the sudden vertical sea-bed movement, due to underwater earthquakes. The results of three dimensional numerical simulations, which solve the wave equation in a weakly compressible sea water domain are presented. The hydro-acoustic signal is compared to an underwater acoustic signal recorded during the event by a scuba diver, who was about 12 km far from the earthquake epicenter
Injectable thermoresponsive hydrogels as drug delivery system for the treatment of central nervous system disorders: A review.
The central nervous system (CNS), consisting of the brain, spinal cord, and retina, superintends to the acquisition, integration and processing of peripheral information to properly coordinate the activities of the whole body. Neurodegenerative and neurodevelopmental disorders, trauma, stroke, and brain tumors can dramatically affect CNS functions resulting in serious and life-long disabilities. Globally, the societal and economic burden associated with CNS disorders continues to grow with the ageing of the population thus demanding for more effective and definitive treatments. Despite the variety of clinically available therapeutic molecules, medical interventions on CNS disorders are mostly limited to treat symptoms rather than halting or reversing disease progression. This is attributed to the complexity of the underlying disease mechanisms as well as to the unique biological microenvironment. Given its central importance, multiple barriers, including the blood brain barrier and the blood cerebrospinal fluid barrier, protect the CNS from external agents. This limits the access of drug molecules to the CNS thus contributing to the modest therapeutic successes. Loco-regional therapies based on the deposition of thermoresponsive hydrogels loaded with therapeutic agents and cells are receiving much attention as an alternative and potentially more effective approach to manage CNS disorders. In this work, the current understanding and challenges in the design of thermoresponsive hydrogels for CNS therapy are reviewed. First, the biological barriers that hinder mass and drug transport to the CNS are described, highlighting the distinct features of each barrier. Then, the realization, characterization and biomedical application of natural and synthetic thermoresponsive hydrogels are critically presented. Advantages and limitations of each design and application are discussed with the objective of identifying general rules that could enhance the effective translation of thermoresponsive hydrogel-based therapies for the treatment of CNS disorders
Galectin-3. One molecule for an alphabet of diseases, from A to Z
Galectin-3 (Gal-3) regulates basic cellular functions such as cell–cell and cell–matrix interactions, growth, proliferation, differentiation, and inflammation. It is not surprising, therefore, that this protein is involved in the pathogenesis of many relevant human diseases, including cancer, fibrosis, chronic inflammation and scarring affecting many different tissues. The papers published in the literature have progressively increased in number during the last decades, testifying the great interest given to this protein by numerous researchers involved in many different clinical contexts. Considering the crucial role exerted by Gal-3 in many different clinical conditions, Gal-3 is emerging as a new diagnostic, prognostic biomarker and as a new promising therapeutic target. The current review aims to extensively examine the studies published so far on the role of Gal-3 in all the clinical conditions and diseases, listed in alphabetical order, where it was analyzed
Cancer rate of the indeterminate lesions at low or high risk according to italian system for reporting of thyroid FNA
Background: Italian consensus for the classification and reporting of thyroid cytology
(ICCRTC) has been used in almost all Italian institutions since 2014. High reliability
of ICCRTC in classifying low and high risk indeterminate nodules (Tir 3A and Tir 3B,
respectively) was demonstrated. Here we reviewed our casuistry of thyroid indeterminate
lesions to analyze the histologic outcome.
Methods: All lesions undergone FNA and final histology at S. Andrea Hospital of Rome
after a cytologic assessment of Tir 3A and Tir 3B, according to ICCRTC, were included
in the study.
Results: A number of 157 indeterminate FNA was found after the introduction of
ICCRTC. Of these, 75 undergone surgery and were finally included for the study. At
histology we found a 33.3% of cancers and a 67.7% of benign lesions. Out of the overall
series, 25 were classified as Tir 3A and 50 as Tir 3B. Cancer rate observed in Tir 3A (1/25,
4%) was significantly (p = 0.0002) lower than that of Tir 3B (24/50, 48%). No significant
difference was found in age and size between the two subcategories.
Conclusions: We confirm in our series that Italian consensus for the classification and
reporting of thyroid cytology allows to discriminate indeterminate lesions at low and high
risk of malignancy
Prototype data analysis of the dynamics of the Venice gate-barriers during an extreme storm event
The MoSE barriers system was designed and constructed at the inlets of the Venice Lagoon (Italy) in order to limit and tame the flooding events in the Lagoon areas and in the City. The success of the design and operation of the system has been demonstrated by the significant reduction in the number and intensity of floods in the lagoon since its beginning of operations in 2020. In this study, we investigate the dynamical behavior of the MoSE system at full-scale by analyzing the barriers behavior during the severe storm event of November 22nd, 2022. In particular, the dynamical response of the Chioggia barrier to waves and storm surge is studied in detail. Spectral analysis of field records, barrier and inlet modal analyses and Empirical Orthogonal Functions (EOF) techniques are applied to provide a key for interpreting the actual behavior of such a complex system during a storm event, highlighting dominant frequencies and checking for the occurrence of resonance phenomena. First, a brief review of the experimental and theoretical studies carried out over the past forty years is given. Modal patterns of gates oscillations detected via EOF analysis confirm the presence of the eigenmodes of both the barrier and the inlet; however, the gates oscillations during the considered event are mild and the hydraulic performances of the system are satisfactory for the severe event studied. Further field measurements and future severe events should be studied to reach extended conclusions
Employment of focused MeV ion microbeams for the fabrication of buried graphitic channels in diamond
Extended mild-slope equations for compressible fluids
In this paper we derive new forms of the mildslope
equation (MSE) for water waves in a
weakly compressible fluid on a slowly varying
bathymetry, with surface and bottom disturbances.
The MSE is a powerful tool to model the
refraction-diffraction dynamics of water waves
propagating on a variable bathymetry [1]. Traditionally,
mild-slope models are derived by assuming
that the wave steepness is small, the fluid
is inviscid and incompressible and the motion
is irrotational. Furthermore, no disturbances
are normally considered both on the free surface
and at the bottom of the fluid domain [2]. In
this paper we shall find new expressions of the
MSE by relaxing the incompressibility hypothesis
and considering both surface and bottom disturbances.
We shall name the set of new formulae
as the extended acoustic-gravity mild-slope
equations (EAG-MSE). Such a system of equations
can be implemented in numerical models
for the early detection of coastal flooding based
on the hydro-acoustic precursors of surface gravity
waves (see [3]–[5])
a depth integrated equation for large scale modeling of tsunami in weakly compressible fluid
Pressure waves generated by fast seabed movement in weakly compressible sea water, namely hydro-acoustic waves travel at the sound celerity in water (about 1500 m/s). These waves are precursors of the counterpart long free-surface gravity waves and contain significant information on the tsunamigenic source. Measurement of hydro-acoustic waves can therefore anticipate the tsunami arrival and significantly enhance the promptness and accuracy of tsunami early warning systems. In this paper derivation of a novel depth-integrated numerical model for reproduction of hydroacoustic waves is presented and the application of this computationally ecient model on two devastating historical tsunamis of Mediterranean Sea in real bathymetry analyzed to reveal the eect of variable bathymetry. On the basis of the model results, some hints for deep sea observatory are given
Tsunamis Generated by Submerged Landslides: Numerical Analysis of the Near-Field Wave Characteristics
ABSTRACT: The accurate modeling of the landslide?generated tsunami characteristics in the so-called near-field is crucial for many practical applications. In this paper, we present a new full-3-D numerical method for modeling tsunamis generated by rigid and impermeable landslides in OpenFOAM® based on the overset mesh technique. The approach has been successfully validated through the numerical reproduction of past experiments for landslide?generated tsunamis triggered by a rigid and impermeable wedge at a sloping coast. The method has been applied to perform a detailed numerical study of the near-field wave features induced by submerged landslides. A parametric analysis has been carried out to explore the importance of the landslide's initial acceleration, directly related to the landslide-triggering mechanisms, on the tsunami generation process and on the related wave properties. Near-field analysis of the numerical results confirms that the influence of the initial acceleration on the tsunami wave properties is significant, affecting wave height, wave period, and wave celerity. Furthermore, it is found that the tsunami generation mechanism experiences a saturation effect for increasing landslide's initial acceleration, confirming and extending previous studies. Moreover, the resulting extended database, composed of previous experimental data and new numerical ones, spanning a wider range of governing parameters, has been represented in the form of a “nondimensional wavemaker curve,” and a new relationship for predicting the wave properties in the near-field as a function of the Hammack number is proposed
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