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Clinical role of non-invasive assessment of portal hypertension

World Journal of Gastroenterology 2017年第1期23卷 1-10页

作者： Massimo Bolognesi marco Di Pascoli David Sacerdoti Department of Medicine University of PadovaI-35128 PadovaItaly

Measurement of portal pressure is pivotal in the evaluation of patients with liver cirrhosis. The measurement of the hepatic venous pressure gradient represents the reference method by which portal pressure is estimated. However, it is an invasive procedure that requires significant hospital resources, including experienced staff, and is associated with considerable cost. Non-invasive methods that can be reliably used to estimate the presence and the degree of portal hypertension are urgently needed in clinical practice. Biochemical and morphological parameters have been proposed for this purpose, but have shown disappointing results overall. Splanchnic Doppler ultrasonography and the analysis of microbubble contrast agent kinetics with contrast-enhanced ultrasonography have shown better accuracy for the evaluation of patients with portal hypertension. A key advancement in the non-invasive evaluation of portal hypertension has been the introduction in clinical practice of methods able to measure stiffness in the liver, as well as stiffness/congestion in the spleen. According to the data published to date, it appears to be possible to rule out clinically significant portal hypertension in patients with cirrhosis (i.e., hepatic venous pressure gradient ≥ 10 mmHg) with a level of clinically-acceptable accuracy by combining measurements of liver stiffness and spleen stiffness along with Doppler ultrasound evaluation. it is probable that the combination of these methods may also allow for the identification of patients with the most serious degree of portal hypertension, and ongoing research is helping to ensure progress in this field.

关键词： Portal hypertension Splenic stiffness Liver stiffness Splenic arterial resistance indices Sonography Doppler ultrasound Cirrhosis Transient elastography Esophageal varices

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Spiral trajectories induced by radial thrust with applications to generalized sails

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Astrodynamics 2021年第2期5卷 121-137页

作者： marco Bassetto Alessandro A.Quarta Giovanni Mengali Vittorio Cipolla Department of Civil and industrial Engineering University of PisaPisaI-56122Italy

in this study,new analytical solutions to the equations of motion of a propelled spacecraft are investigated using a shape-based *** is an assumption that the spacecraft travels a two-dimensional spiral trajectory in which the orbital radius is proportional to an assigned power of the spacecraft angular *** exact solution to the equations of motion is obtained as a function of time in the case of a purely radial thrust,and the propulsive acceleration magnitude necessary for the spacecraft to track the prescribed spiral trajectory is found in a closed *** analytical results are then specialized to the case of a generalized sail,that is,a propulsion system capable of providing an outward radial propulsive acceleration,the magnitude of which depends on a given power of the Sun-spacecraft *** particular,the conditions for an outward radial thrust and the required sail performance are quantified and thoroughly *** is worth noting that these propulsion systems provide a purely radial thrust when their orientation is *** is an important advantage from an engineering point of view because,depending on the particular propulsion system,a Sun-facing attitude can be stable or obtainable in a passive way.A case study is finally presented,where the generalized sail is assumed to start the spiral trajectory from the Earth’s heliocentric *** main outcome is that the required sail performance is in principle achievable on the basis of many results available in the literature.

关键词： radial thrust spiral trajectory shape-based approach analytical solution generalized sail

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Morbidity and psychological impact of prostate biopsy： the future calls for a change

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Asian Journal of Andrology 2014年第3期16卷 415-417页

作者： Andrea Minervini Gianni Vittori Giampaolo Siena marco Carini Department of Urology University of FlorenceCareggi Hospital Florence Italy.

Currently transrectal ultrasound-guided prostate biopsy （TRUS-Bx） is one of the most common urological procedures, with more than 1 million performed per year in Europe and the United States. Among patients undergoing TRUS-Bx, approximately one-third will receive a diagnosis of prostate cancer （PCa）, while two-thirds receive a negative result on initial biopsy. Negative biopsy patients maintain an estimated risk of repeated biopsy of 12% at i year and 38% at 5 years. 2 Standard TRUS-Bx is likely to systematically miss significant tumors, particularly in the anterior and apical parts of the gland.3 A crucial aim of urologists in the next decade is to increase the accuracy of the procedure and avoid the use of inappropriate biopsies.

关键词： Morbidity psychological impact prostate biopsy

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Optimal interplanetary trajectories for Sun-facing ideal diffractive sails

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Astrodynamics 2023年第3期7卷 285-299页

作者： Alessandro A.Quarta Giovanni Mengali marco Bassetto Lorenzo Niccolai Department of Civil and industrial Engineering University of PisaI-56122 PisaItaly

A diffractive sail is a solar sail whose exposed surface is covered by an advanced diffractive metamaterial film with engineered optical properties. This study examines the optimal performance of a diffractive solar sail with a Sun-facing attitude in a typical orbit-to-orbit heliocentric transfer. A Sun-facing attitude, which can be passively maintained through the suitable design of the sail shape, is obtained when the sail nominal plane is perpendicular to the Sun–spacecraft line. Unlike an ideal reflective sail, a Sun-facing diffractive sail generates a large transverse thrust component that can be effectively exploited to change the orbital angular momentum. Using a recent thrust model, this study determines the optimal control law of a Sun-facing ideal diffractive sail and simulates the minimum transfer times for a set of interplanetary mission scenarios. it also quantifies the performance difference between Sun-facing diffractive sail and reflective sail. A case study presents the results of a potential mission to the asteroid 16 Psyche.

关键词： diffractive solar sail Sun-facing sail interplanetary transfer trajectory optimization

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A Finite Element Study of the influence of Graphite Nodule Characteristics on a Subsurface Crack in a Ductile Cast iron Matrix under a Contact Load

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Computer Modeling in Engineering & Sciences 2018年第10期117卷 59-71页

作者： Guilherme Suguinoshita Carlos Henrique da Silva marco Antonio Luersen Department of Mechanical Engineering Federal University of Technology-Parana(UTFPR)Rua Deputado Heitor Alencar Furtado5000CEP 81280-340CuritibaBrazil

This paper describes a study of the effects of graphite nodule characteristics on a subsurface crack in austempered ductile iron(ADi).A representative specimen of ADi,subjected to sliding contact load,is modeled using finite elements aiming to obtain the shear stress intensity factor(Kii).The parameters varied were(i)the nodule diameter(two different values were considered),(ii)the distance between the nodule and the tip of the crack and(iii)the position of the load relative to the tip of the *** results of the numerical simulations show that the smaller diameter nodule has a larger influence on Kii,suggesting a higher contact fatigue crack propagation rate in the material with the smaller *** results are the opposite of those observed in experimental studies and would appear to indicate that other factors should be also considered to ensure realistic estimates of the contact fatigue strength of ADi.

关键词： Austempered ductile iron subsurface crack stress intensity factor finite element analysis graphite nodule

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Landslide on glaciers: an example from Western Alps(Cogne-italy)

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Journal of Mountain Science 2020年第5期17卷 1161-1171页

作者： FRASCA marco VACHA Damiano CHiCCO Jessica TROiLO Fabrizio BERTOLO Davide Fondazione Montagna Sicura Localita Villard de la Palud 111013 CourmayeurAostaItaly Universita degli Studi di Torino Department of Earth SciencesVia Valperga Caluso 3510125 TorinoItaly Regione Autonoma Valle d'Aosta-Assessorato alle opere pubbliche territorio ed edilizia residenziale pubblicaLocalita Ameriquen.3311020 QuartAostaItaly

in the warm summer of 2017,a landslide failed from the south-east side of the Col des Clochettes on the top of the underlying Trajo *** study area is at an elevation of about 3500 m *** the Gran Paradiso Massif and can be hardly reached by walking from Cogne(Aosta Valley,NW italy).Studies conducted by field surveys,photogrammetry(structure from motion)and satellite images analysis,integrated with the evaluation of data from meteorological stations have been used to reconstruct the phenomenon and infer its *** site is very complex to be studied especially due to logistic problems,therefore,measurements and observations that are common practice in other landslides are very difficult to apply ***,many of the results achieved are not adequately supported by field ***,the following factors could have affected the stability of the slope:i)the tectonic structure of the area,which is reflected on the morphology and on the geomechanics characteristics of the rock masses;ii)the meteorological conditions during 3 months before the main failure,resulting in an extremely high temperature compared to historical ***,the analysis of multitemporal satellite images allowed to recognize that it was not a single landslide but that the phenomenon is articulated over time in at least five failures in about 2 ***,several predisposing factors may have been playing an important role in causing the instability:the degradation of permafrost(probably affecting rock mass due to the circulation of warm air and water in the discontinuity systems),the alternance of the freeze-thaw cycles and the availability of a considerable amount of water from rainfalls and nival fusion infiltrating deeply in the rock *** common causes such as rains and earthquakes have been excluded.

关键词： Landslide Glacier Remote sensing Climate changes Western italian Alps

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New perspectives in iron chelation therapy for the treatment of Parkinson’s disease

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Neural Regeneration Research 2019年第11期14卷 1905-1906页

作者： marco T. Nunez Pedro Chana-Cuevas Faculty of Sciences Universidad de ChileSantiagoChile Movement Disorders Center Universidad de Santiago de ChileSantiagoChile

Neurodegenerative diseases with an iron accumulation component: A wide variety of neurological diseases are characterized by the accumulation of iron in different areas of the central nervous system, include Parkinson’s disease, Huntington disease, Alzheimer’s disease, Friedreich’s ataxia, amyotrophic lateral sclerosis, pantothenate kinase-associated neurodegeneration and other neuropathologies associated with brain iron accumulation (Hayflick et al., 2018).

关键词： Parkinson Huntington Friedreich Alzheimer

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Factors influencing the drug release from calcium phosphate cements

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Bioactive Materials 2022年第1期7卷 341-363页

作者： marco Fosca Julietta V.Rau Vuk Uskokovi istituto di Struttura della Materia Consiglio Nazionale delle Ricerche(ISM-CNR)Via del Fosso del Cavaliere 10000133RomeItaly i.M.Sechenov First Moscow State Medical University Institute of PharmacyDepartment of AnalyticalPhysical and Colloid ChemistryTrubetskaya 8build.2119991MoscowRussia Advanced Materials and Nanobiotechnology Laboratory TardigradeNano LLCIrvineCA 92604United States

Thanks to their biocompatibility,biodegradability,injectability and self-setting properties,calcium phosphate cements(CPCs)have been the most economical and effective biomaterials of choice for use as bone void *** have also been extensively used as drug delivery carriers owing to their ability to provide for a steady release of various organic molecules aiding the regeneration of defective bone,including primarily antibiotics and growth *** review provides a systematic compilation of studies that reported on the controlled release of drugs from CPCs in the last 25 *** chemical,compositional and microstructural characteristics of these systems through which the control of the release rates and mechanisms could be achieved have been *** doing so,the effects of(i)the chemistry of the matrix,(ii)porosity,(iii)additives,(iv)drug types,(v)drug concentrations,(vi)drug loading methods and(vii)release media have been distinguished and discussed *** specificities of in vivo release of drugs from CPCs have been reviewed,*** the kinetic and mechanistic correlations between the CPC properties and the drug release is a prerequisite for the design of bone void fillers with drug release profiles precisely tailored to the application area and the clinical *** goal of this review has been to shed light on these fundamental correlations.

关键词： Calcium phosphate cements Drug release Release rate Antibiotics release Bone fillers

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Natural and Eco-Friendly Materials for Triboelectric Energy Harvesting

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Nano-Micro Letters 2020年第3期12卷 179-196页

作者： Vladislav Slabov Svitlana Kopyl marco PSoares dos Santos Andrei L.Kholkin Department of Physics and CiCECO‑Aveiro institute of Materials University of Aveiro3810‑193 AveiroPortugal Centre for Mechanical Technology and Automation(TEMA) University of Aveiro3810‑193 AveiroPortugal Department of Mechanical Engineering University of Aveiro3810‑193 AveiroPortugal School of Natural Sciences and Mathematics Ural Federal UniversityEkaterinburgRussia 620000 Laboratory of Functional Low‑Dimensional Structures National University of Science and Technology MISiSMoscowRussia 119049

Triboelectric nanogenerators(TENGs)are promising electric energy harvesting devices as they can produce renewable clean energy using mechanical excitations from the *** designs of triboelectric energy harvesters relying on biocompatible and eco-friendly natural materials have been introduced in recent *** ability to provide customizable self-powering for a wide range of applications,including biomedical devices,pressure and chemical sensors,and battery charging appliances,has been *** review summarizes major advances already achieved in the field of triboelectric energy harvesting using biocompatible and eco-friendly natural materials.A rigorous,comparative,and critical analysis of preparation and testing methods is also *** power up to 14 mW was already achieved for the dry leaf/polyvinylidene fluoride-based TENG *** findings highlight the potential of eco-friendly self-powering systems and demonstrate the unique properties of the plants to generate electric energy for multiple applications.

关键词： Natural and eco-friendly materials Energy harvesting Triboelectric nanogenerators Biocompatibility

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Colorectal cancer screening:The role of CT colonography

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World Journal of Gastroenterology 2010年第32期16卷 3987-3994页

作者： Andrea Laghi Franco iafrate marco Rengo Cesare Hassan Department of Radiological Sciences Sapienza-Università di RomaPolo PontinoLatina 04100Italy Department of Radiological Sciences Sapienza-Università di RomaPoliclinico Umberto IRome 00161Italy Gastroenterology and Digestive Endoscopy Unit ''Nuovo Regina Margherita'' HospitalRome 00153Italy

Computed tomography colonography(CTC) in colorectal cancer(CRC) screening has two roles:one present and the other *** present role is,without any further discussion,the integration into established screening programs as a replacement for barium enema in the case of incomplete *** potential role is the use of CTC as a first-line screening method together with Fecal Occult Blood Test,sigmoidoscopy and ***,despite the fact that CTC has been officially endorsed for CRC screening of average-risk individuals by different scientif ic societies including the American Cancer Society,the American College of Radiology,and the US Multisociety Task Force on Colorectal Cancer,other entities,such as the US Preventive Services Task Force,have considered the evidence insuff icient to justify its use as a mass screening *** has also recently denied reimbursement for CTC as a screening ***,multiple advantages exist for using CTC as a CRC screening test:high accuracy,full evaluation of the colon in virtually all patients,non-invasiveness,safety,patient comfort,detection of extracolonic findings and *** main potential drawback of a CTC screening is the exposure to ionizing ***,this is not a major issue,since low-dose protocols are now routinely implemented,delivering a dose comparable or slightly superior to the annual radiation exposure of any *** evidence exists that such a radiation exposure does not induce additional cancers.

关键词： Computed tomography colonography Colon neoplasms Colon polyps Colorectal cancer screening Computed tomography colonography safety Computed tomography colonography accuracy Computed tomography colonography radiation exposure Computed tomography colonography cost-effectiveness

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