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Energy flow in negative index materials

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Chinese Optics Letters 2004年第7期2卷 428-430页

作者： lorenzo Bolla Michele Midrio Carlo G.Someda The Istituto Nazionale per la Fisica della Materia (I. N. F. M.) Dipartimento di Ingegneria Elettrica Gestionale e Meccanica Universita degli Studi di Udine viale delle Scienze 208 33100 Udine Italy I. N. F. M. Dipartimento di Ingegneria dell'Informazione via G. Gradenigo 6/B 35131 Padova Italy

Prom Maxwell's equations, we compute the speed and the direction of propagation of active power refracted from air into a negative index material. We prove, both analytically and numerically that the power may refract positively even if phase fronts refract negatively. Considerations on the usage of ray optics in problems involving negative index materials are drawn.

关键词： Geometric optics Negative index materials

Management of gastro-esophageal reflux disease:Practice-oriented answers to clinical questions

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World Journal of Gastroenterology 2023年第5期29卷 773-779页

作者： Leonardo Frazzoni lorenzo Fuccio Rocco Maurizio Zagari Department of Digestive Diseases IRCCS Azienda Ospedaliero-Universitaria di Bologna Policlinico S OrsolaBologna 40138Italy Department of Medical and Surgical Sciences University of BolognaBologna 40138Italy

Gastro-esophageal reflux disease(GERD)is a condition which is frequently faced by primary care physicians and *** management of GERD is crucial to maximise both patient care and resource *** fact,the management of patients with GERD is complex and poses several questions to the clinician who faces them in clinical *** instance,many aspects should be considered,including the appropriateness of indication to endoscopy,the quality of the endoscopic examination,the use and interpretation of ambulatory reflux testing,and the choice and management of anti-reflux treatments,i.e.,protonpump inhibitors and *** of the present review was to provide a comprehensive update on the clinical management of patients with GERD,through a literature review on the diagnosis and management of patients with GER *** details,we provide practice-oriented concise answers to clinical questions,with the aim of optimising patient management and healthcare resource use.

关键词： Gastro-esophageal reflux disease Diagnosis Management Proton-pump inhibitor

Management of obstructed defecation

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World Journal of Gastroenterology 2015年第4期21卷 1053-1060页

作者： Vlasta Podzemny lorenzo Carlo Pescatori Mario Pescatori Coloproctology Unit Parioli Clinic00100 RomeItaly

The management of obstructed defecation syndrome(ODS) is mainly conservative and mainly consists of fiber diet, bulking laxatives, rectal irrigation or hydrocolontherapy, biofeedback, transanal electrostimulation, yoga and psychotherapy. According to our experience, nearly 20% of the patients need surgical treatment. If we consider ODS an "iceberg syndrome", with "emerging rocks", rectocele and rectal internal mucosal prolapse, that may benefit from surgery, at least two out of ten patients also has "underwater rocks" or occult disorders, such as anismus, rectal hyposensation and anxiety/depression, which mostly require conservative treatment. Rectal prolapse excision or obliterative suture, rectoceleand/or enterocele repair, retrograde Malone's enema and partial myotomy of the puborectalis muscle are effective in selected cases. Laparoscopic ventral sacral colporectopexy may be an effective surgical option. Stapled transanal rectal resection may lead to severe complications. The Transtar procedure seems to be safer, when dealing with recto-rectal intussusception. A multidisciplinary approach to ODS provides the best results.

关键词： Constipation Obstructed defecation Pelvic floor re

Phenolic compounds of green tea: Health benefits and technological application in food

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Asian Pacific Journal of Tropical Biomedicine 2016年第8期6卷 709-719页

作者： Jose Manuel lorenzo Paulo Eduardo Sichetti Munekata Meat Technological Center of Galicia Galicia Street No.4 Parque Tecnolgico de Galicia San Cibrao das Vinas Department of Food Engineering Faculty of Animal Science and Food Engineering University of Sao Paulo

Green tea has been an important beverage for humans since ancient times, widely consumed and considered to have health benefits by traditional medicine in Asian countries. Green tea phenolic compounds are predominately composed of catechin derivatives, although other compounds such as flavonols and phenolic acids are also present in lower proportion. The bioactivity exerted by these compounds has been associated with reduced risk of severe illnesses such as cancer, cardiovascular and neurodegenerative diseases. Particularly, epigallocatechin gallate has been implicated in alteration mechanisms with protective effect in these diseases as indicated by several studies about the effect of green tea consumption and mechanistic explanation through in vitro and in vivo experiments. The biological activity of green tea phenolic compounds also promotes a protective effect by antioxidant mechanisms in biological and food systems, preventing the oxidative damage by acting over either precursors or reactive species. Extraction of phenolic compounds influences the antioxidant activity and promotes adequate separation from green tea leaves to enhance the yield and/or antioxidant activity. Application of green tea phenolic compounds is of great interest because the antioxidant status of the products is enhanced and provides the product with additional antioxidant activity or reduces the undesirable changes of oxidative reactions while processing or storing *** this scenario, meat and meat products are greatly influenced by oxidative deterioration and microbial spoilage, leading to reduced shelf life. Green tea extracts rich in phenolic compounds have been applied to increase shelf life with comparable effect to synthetic compounds, commonly used by food industry. Green tea has great importance in general health in technological application, however more studies are necessary to elucidate the impact in pathways related to other diseases and food applications.

关键词： Phenolic profile Healthy Neurodegenerative diseases Extraction of polyphenols Antioxidant mechanism Food stability

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

Stratigraphy of the Alveolina elliptica group from the Middle Eocene of Iran:Calibration with calcareous nannofossils biozones and description of Alveolina ozcani n. sp.

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Journal of Palaeogeography 2024年第1期13卷 54-79页

作者： Mehdi Hadi lorenzo Consorti Ali Bahrami Mohammad Parandavar Saeed Khorramdel Department of Geology Faculty of SciencesUniversity of IsfahanIsfahanIran Institute of Marine Sciences(ISMAR-CNR) Area Science ParkBasovizza34149 TriesteItaly National Iranian Oil Company Exploration DirectorateSheikh Bahaei SquareTehranIran Department of Geology Faculty of ScienceFerdowsi University of MashhadMashhadIran

Precise taxonomy and the chronostratigraphic calibration of the Middle Eocene Alveolina from Central Iran is here undertaken from the Chah-Talkh section of the southern Sabzevar region(Central Iran). We have identified Alveolina kieli, Alveolina stercusmuris and Alveolina nuttalli along with the new species Alveolina ozcani n. sp. that we include into the Alveolina elliptica group. We have also found Nummulites uroniensis, Nummulites obesus and Nummulites cf. verneuili and associated calcareous nannofossils that look reliable to make thoughtful correlations with the Shallow Benthic Zones(SBZ). The foraminiferal biostratigraphy suggests an assignment to the upper part of the lower Lutetian-lower part of the middle Lutetian,SBZ13(Middle Eocene), further strengthened through the identification of the calcareous nannofossil NP14b-NP15b or CNE8-CNE10 biozones, providing a solid correlation with the global stratigraphic standards.

关键词： Alveolina Calcareous nannofossil Central neo-tethys Central Iran Middle Eocene Biostratigraphy

Mechanisms of electrochemical magnesium(de)alloying of Mg-Sn and Mg-Pb polymorphs

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Journal of Magnesium and Alloys 2022年第6期10卷 1609-1616页

作者： Clément Pechberty Antoine Klein Bernard Fraisse lorenzo Stievano Romain Berthelot ICGM CNRSUniv.MontpellierENSCMMontpellierFrance RS2E CNRSHub de l’EnergieAmiensFrance

Different polymorphs of Mg-Sn and Mg-Pb intermetallic compounds were prepared by high-energy mechanical alloying and then investigated as active material in magnesium batteries. Beside thermodynamically stable Mg_(2)Sn and Mg_(2)Pb crystallizing in the anti-fluorite structure, other polymorphs Mg_(~2)Sn and Mg_(~2)Pb were prepared by increasing the ball-milling time. The first dealloying process is almost complete only for the cubic polymorphs, then similar capacities are observed during the subsequent alloying and dealloying *** to operando X-ray diffraction, the electrochemical mechanism is revealed and shows that the cubic polymorphs Mg_(2)Sn and Mg_(2)Pb tend to preferentially form during the alloying whatever the pristine intermetallic. Weak traces of Mg_(~2)Sn and Mg_(~2)Pb are observed during the alloying, suggesting that these polymorphs act as a by-product and/or an intermediate phases of the electrochemical process. Finally, the compatibility of cubic Mg_(2)Sn and Mg_(2)Pb with Mg(TFSI)_(2)-based electrolyte is confirmed in full cell vs. a positive electrode based on the Chevrel phase Mo6S8, although limited performance is achieved. This fundamental work provides new insights in the behavior of alloy-type negative electrodes for magnesium-ion batteries.

关键词： Magnesium batteries Alloy electrode Mechanochemistry Operando X-ray diffraction

Spatio-temporal visualization of light transport in complex photonic structures

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Light(Science & Applications) 2016年第1期5卷 714-722页

作者： lorenzo Pattelli Romolo Savo Matteo Burresi Diederik S Wiersma European Laboratory for Non-linear Spectroscopy(LENS) Universitàdi FirenzeSesto Fiorentino(FI)50019Italy Istituto Nazionale di Ottica(CNR-INO) Firenze(FI)50125Italy Dipartimento di Fisica e Astronomia Universitàdi FirenzeSesto Fiorentino(FI)50019Italy Laboratoire Kastler Brossel UMR 8552CNRSEcole Normale SupérieureUniversitéPierre et Marie CurieCollège de France24 rue LhomondParis 75005France Gestione SILO Srl via di Castelpulci 14/dScandicci(FI)50010Italy

Spatio-temporal imaging of light propagation is very important in photonics because it provides the most direct tool available to study the interaction between light and its host ***-ps time resolution is needed to investigate the fine and complex structural features that characterize disordered and heterogeneous structures,which are responsible for a rich array of transport physics that have not yet been fully explored.A newly developed wide-field imaging system enables us to present a spatiotemporal study on light transport in various disordered media,revealing properties that could not be properly assessed using standard *** extending our investigation to an almost transparent membrane,a configuration that has been difficult to characterize until now,we unveil the peculiar physics exhibited by such thin scattering systems with transport features that go beyond mainstream diffusion modeling,despite the occurrence of multiple scattering.

关键词： diffusive approximation disordered media light transport optical gating wide-field imaging

Analysis of the cryptocurrency market using different prototype-based clustering techniques

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Financial Innovation 2022年第1期8卷 141-186页

作者： Luis lorenzo Javier Arroyo Un iversidad Complute nse de Madrid Facultad de Estudios Estadisticos Madrid MadridSpain

Since the emergence of Bitcoin,cryptocurrencies have grown significantly,not only in terms of capitalization but also in ***,the cryptocurrency market can be a conducive arena for investors,as it offers many ***,it is difficult to *** study aims to describe,summarize,and segment the main trends of the entire cryptocurrency market in 2018,using data analysis ***-ingly,we propose a new clustering-based methodology that provides complementary views of the financial behavior of cryptocurrencies,and one that looks for associations between the clustering results,and other factors that are not involved in ***,the methodology involves applying three different partitional clustering algorithms,where each of them use a different representation for cryptocurrencies,namely,yearly mean,and standard deviation of the returns,distribution of returns that have not been applied to financial markets previously,and the time series of *** each representation provides a different outlook of the market,we also examine the integration of the three clustering results,to obtain a fine-grained analysis of the main trends of the *** conclusion,we analyze the association of the clustering results with other descriptive features of cryptocurrencies,including the age,technological attributes,and financial ratios derived from *** will help to enhance the profiling of the clusters with additional descriptive insights,and to find associations with other ***,this study describes the whole market based on graphical information,and a scalable methodology that can be reproduced by investors who want to understand the main trends in the market quickly,and those that look for cryptocurrencies with different financial *** our analysis of the 2018 and 2019 for extended period,we found that the market can be typically segmented in few clusters(five or less),and even considering the

关键词： Fintech Unsupervised machine learning Cryptocurrency Electronic market Clustering Investment portfolios