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1.
IEEE Trans Microw Theory Tech ; 70(10): 4579-4589, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-36846311

RESUMO

A digital-impulse galvanic coupling as a new high-speed trans-dural (from cortex to the skull) data transmission method has been presented in this paper. The proposed wireless telemetry replaces the tethered wires connected in between implants on the cortex and above the skull, allowing the brain implant to be "free-floating" for minimizing brain tissue damage. Such trans-dural wireless telemetry must have a wide channel bandwidth for high-speed data transfer and a small form factor for minimum invasiveness. To investigate the propagation property of the channel, a finite element model is developed and a channel characterization based on a liquid phantom and porcine tissue is performed. The results show that the trans-dural channel has a wide frequency response of up to 250 MHz. Propagation loss due to micro-motion and misalignments is also investigated in this work. The result indicates that the proposed transmission method is relatively insensitive to misalignment. It has approximately 1 dB extra loss when there is a horizontal misalignment of 1mm. A pulse-based transmitter ASIC and a miniature PCB module are designed and validated ex-vivo with a 10-mm thick porcine tissue. This work demonstrates a high-speed and miniature in-body galvanic-coupled pulse-based communication with a data rate up to 250 Mbps with an energy efficiency of 2 pJ/bit, and has a small module area of only 26 mm2.

2.
Radiol Med ; 126(1): 170-177, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32377914

RESUMO

OBJECTIVES: To evaluate the incidence and clinical significance of pneumothorax (PTX) and pulmonary hemorrhage (PH) after CT-guided lung biopsy (CT-LB). To test correlations of PTX and chest tube insertion (CTI) with PH and other imaging and procedural parameters. METHODS: Pre-procedural CT and CT-LB scans of 904 patients were examined. Incidence of PTX and PH and PH location (type-1 along needle track; type-2 perilesional) and severity according to its thickness (low grade < 6 mm; high grade > 6 mm) were recorded. PTX was considered clinically significant if treated with CTI, PH if treated with endoscopic/endovascular procedure. Binary logistic regression analyses were used to determine the effects of different imaging and procedural parameters on the likelihood to develop PTX, CTI and PH and to define their correlation. RESULTS: PTX occurred in 306/904 cases (33.8%); CTI was required in 18/306 (5.9%). PH occurred in 296/904 cases (32.7%), and no case required treatment. Nodule-to-pleura distance (ORPTX = 1.052; ORCTI = 1.046; ORPH 1.077), emphysema (ORPTX = 1.287; ORPH = 0.573), procedure time (ORPTX = 1.019; ORCTI = 1.039; ORPH = 1.019), target size (ORPTX = 0.982; ORPH = 0.968) and needle gauge (ORPTX = 0.487; ORCTI = 4.311; ORPH = 2.070) showed statistically significant correlation to PTX, CTI and PH. Type-1 PH showed a protective effect against PTX and CTI (ORPTX = 0.503; ORCTI = 0.416). CONCLUSION: PTX and PH have similar incidence after CT-guided lung biopsy. PH along needle track may represent a protective factor against development of PTX and against PTX requiring CTI.


Assuntos
Hemorragia/etiologia , Biópsia Guiada por Imagem/efeitos adversos , Pneumopatias/patologia , Lesão Pulmonar/etiologia , Pneumotórax/etiologia , Tomografia Computadorizada por Raios X , Idoso , Feminino , Hemorragia/epidemiologia , Humanos , Doença Iatrogênica , Incidência , Lesão Pulmonar/epidemiologia , Masculino , Pessoa de Meia-Idade , Pneumotórax/epidemiologia , Fatores de Risco
3.
Sci Rep ; 12(1): 19175, 2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36357471

RESUMO

Ongoing resurgence affects Campi Flegrei caldera (Italy) via bradyseism, i.e. a series of ground deformation episodes accompanied by increases in shallow seismicity. In this study, we perform a mathematical analysis of the GPS and seismic data in the instrumental catalogs from 2000 to 2020, and a comparison of them to the preceding data from 1983 to 1999. We clearly identify and characterize two overlying trends, i.e. a decennial-like acceleration and cyclic oscillations with various periods. In particular, we show that all the signals have been accelerating since 2005, and 90-97% of their increase has occurred since 2011, 40-80% since 2018. Nevertheless, the seismic and ground deformation signals evolved differently-the seismic count increased faster than the GPS data since 2011, and even more so since 2015, growing faster than an exponential function The ground deformation has a linearized rate slope, i.e. acceleration, of 0.6 cm/yr2 and 0.3 cm/yr2 from 2000 to 2020, respectively for the vertical (RITE GPS) and the horizontal (ACAE GPS) components. In addition, all annual rates show alternating speed-ups and slow-downs, consistent between the signals. We find seven major rate maxima since 2000, one every 2.8-3.5 years, with secondary maxima at fractions of the intervals. A cycle with longer period of 6.5-9 years is also identified. Finally, we apply the probabilistic failure forecast method, a nonlinear regression that calculates the theoretical time limit of the signals going to infinity (interpreted here as a critical state potentially reached by the volcano), conditional on the continuation of the observed nonlinear accelerations. Since 2000, we perform a retrospective analysis of the temporal evolution of these forecasts which highlight the periods of more intense acceleration. The failure forecast method applied on the seismic count from 2001 to 2020 produces upper time limits of [0, 3, 11] years (corresponding to the 5th, 50th and 95th percentiles, respectively), significantly shorter than those based on the GPS data, e.g. [0, 6, 21] years. Such estimates, only valid under the model assumption of continuation of the ongoing decennial-like acceleration, warn to keep the guard up on the future evolution of Campi Flegrei caldera.

4.
Proc Math Phys Eng Sci ; 476(2242): 20200161, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33214757

RESUMO

Statistical emulators are a key tool for rapidly producing probabilistic hazard analysis of geophysical processes. Given output data computed for a relatively small number of parameter inputs, an emulator interpolates the data, providing the expected value of the output at untried inputs and an estimate of error at that point. In this work, we propose to fit Gaussian Process emulators to the output from a volcanic ash transport model, Ash3d. Our goal is to predict the simulated volcanic ash thickness from Ash3d at a location of interest using the emulator. Our approach is motivated by two challenges to fitting emulators-characterizing the input wind field and interactions between that wind field and variable grain sizes. We resolve these challenges by using physical knowledge on tephra dispersal. We propose new physically motivated variables as inputs and use normalized output as the response for fitting the emulator. Subsetting based on the initial conditions is also critical in our emulator construction. Simulation studies characterize the accuracy and efficiency of our emulator construction and also reveal its current limitations. Our work represents the first emulator construction for volcanic ash transport models with considerations of the simulated physical process.

5.
Sci Rep ; 10(1): 17357, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060646

RESUMO

Stromboli volcano (Italy), always active with low energy explosive activity, is a very attractive place for visitors, scientists, and inhabitants of the island. Nevertheless, occasional more intense eruptions can present a serious danger. This study focuses on the modeling and estimation of their inter-event time and temporal rate. With this aim we constructed a new historical catalog of major explosions and paroxysms through a detailed review of scientific literature of the last ca. 140 years. The catalog includes the calendar date and phenomena descriptions for 180 explosive events, of which 36 were paroxysms. We evaluated the impact of the main sources of uncertainty affecting the historical catalog. In particular, we categorized as uncertain 45 major explosions that reportedly occurred before 1985 and tested the effect of excluding these events from our analysis. Moreover, after analyzing the entire record in the period [1879, 2020], we separately considered, as sequences, events in [1879, 1960] and in [1985, 2020] because of possible under recording issues in the period [1960, 1985]. Our new models quantify the temporal rate of major explosions and paroxysms as a function of time passed since the last event occurred. Recurrence hazard levels are found to be significantly elevated in the weeks and months following a major explosion or paroxysm, and then gradually decrease over longer periods. Computed hazard functions are also used to illustrate a methodology for estimating order-of-magnitude individual risk of fatality under certain basis conditions. This study represents a first quantitatively formal advance in determining long-term hazard levels at Stromboli.

6.
Acta Biomed ; 90(5-S): 62-67, 2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31085974

RESUMO

Percutaneous Needle Biopsy (PNB) is the insertion of a needle into a suspected lesion or an organ with the aim to obtain cells or tissue for diagnosis. It's a relatively non-invasive procedure and is performed by radiologist under guidance of imaging techniques such as ultrasound (US), computed tomography (CT), fluoroscopy, magnetic resonance imaging (MRI), and positron emission tomography CT (PET-CT). The choice of imaging technique depends on the evaluation of the target lesion and patient compliance. PNB includes two categories: fine-needle aspiration biopsy (FNAB) that is the use of a thin needle (18-25 gauge) to extract cells for cytological evaluation; and core needle biopsy (CNB) that is the use of a larger needle (9-20 gauge) to extract a piece of tissue for histological evaluation. The indications for biopsy are the characterization of nature (benign or malignant) of a lesion, diagnosis and staging of tumor, and biological or immunohistochemical/genetic analisys on tissue. Success of PNB is the procurement of sufficient material to characterize lesions and to guide the patient outcome.  Major complications are rare. PNB became a useful technique in diagnosis and study of retroperitoneal lesions, because of a more suitable access to specific intra-abdominal structures, lowering the risk of injury of interposed structures (such as bowel, great vessels).


Assuntos
Biópsia por Agulha Fina/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias Retroperitoneais/diagnóstico , Ultrassonografia Doppler em Cores/métodos , Humanos , Espaço Retroperitoneal
7.
Acta Biomed ; 90(5-S): 95-100, 2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31085978

RESUMO

Rotator cuff calcific tendinopathy (RCCT) is a common and painful shoulder disease characterised  by deposition of calcium into the rotator cuff's tendond. Different therapeutic options have been proposed, but the ultrasound-guided percutaneous irrigation (US-PICT) is been proved as an effective and safe first-line treatment. It can be performed with a single- of a double-needle tecnique, using warm saline solution to improve the dissolution of the calcific deposit. The procedure is ended with an intrabursal injection of local anaesthetics and slow-release steroids to improve the pain relief and to prevent complications. US-PICT leads to significative improvement in the shoulder funtion and pain relief in the short and long term, with a low complications rate.


Assuntos
Anestesia Local/métodos , Calcinose/complicações , Manguito Rotador/diagnóstico por imagem , Dor de Ombro/terapia , Tendinopatia/terapia , Ultrassonografia de Intervenção/métodos , Anestésicos Locais/uso terapêutico , Artroscopia/métodos , Calcinose/diagnóstico , Calcinose/terapia , Humanos , Dor de Ombro/diagnóstico , Dor de Ombro/etiologia , Tendinopatia/complicações , Tendinopatia/diagnóstico , Irrigação Terapêutica
8.
Urologia ; 80(1): 46-55, 2013.
Artigo em Italiano | MEDLINE | ID: mdl-23354916

RESUMO

Nanotechnology is a multidisciplinary field originating from the interaction of several different disciplines, such as engineering, physics, biology and chemistry. New materials and devices effectively interact with the body at molecular level, yielding a brand new range of highly selective and targeted applications designed to maximize the therapeutic efficiency while reducing the side effects. Liposomes, quantum dots, carbon nanotubes and superparamagnetic nanoparticles are among the most assessed nanotechnologies. Meanwhile, other futuristic platforms are paving the way toward a new scientific paradigm, able to deeply change the research path in the medical science. The growth of nanotechnology, driven by the dramatic advances in science and technology, clearly creates new opportunities for the development of the medical science and disease treatment in human health care. Despite the concerns and the on-going studies about their safety, nanotechnology clearly emerges as holding the promise of delivering one of the greatest breakthroughs in the history of medical science.


Assuntos
Nanotecnologia/tendências , Sistemas de Liberação de Medicamentos/efeitos adversos , Previsões , Humanos , Lipossomos , Nanomedicina/tendências , Nanopartículas , Nanotubos de Carbono , Pontos Quânticos
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