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The Space and Time Features of Global SST Anomalies Studied by Complex Principal Component Analysis

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Advances in Atmospheric Sciences 1999年第1期16卷 3-23,5+9+11+15+17+19+21页

作者：骆美霞 dipartimento di Fisica Generale Universita di Torino Turin Italy and Istituto di Cosmogeofisica del CNR Turin Italy

In this paper, the variability characteristics of the global field of sea surface temperature (SST) anomaly are studied by complex principal component (c.p.c.) analysis, whose results are also compared with those of real p.c. analysis. The data consist of 40 years of global SST monthly averages over latitudes from 42 5°S to 67 5°N. In the spatial domain, it is found that the distribution of the first complex loading amplitude is characterized by three areas of large values: the first one in the eastern and central equatorial Pacific Ocean, the second one in the northern tropical Indian Ocean and South China Sea, the third one in the northern Pacific Ocean. As it will be explained, this pattern may be considered as representative of El Nio mode. The first complex loading phase pattern shows a stationary wave in the Pacific (also revealed by real p.c. analysis) superimposed to an oscillating disturbance, propagating from the Pacific to Indian or the opposite way. A subsequent correlation analysis among different spatial points allows revealing disturbances actually propagating westward from the Pacific to the Indian Ocean, which could therefore represent reflected Rossby waves, i.e. the west phase of the signals that propagate disturbances of thermal structure in the tropical Pacific Ocean. In the time domain, a relation between the trend of the first complex principal component and the ENSO cycle is also established.

关键词： Global sea surface temperature anomalies ENSO Complex principal component analysis Travelling disturbances

Fault on-off versus strain rate and earthquakes energy

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Geoscience Frontiers 2015年第2期6卷 265-276页

作者： C.Doglioni S.Barba E.Carminati F.Riguzzi dipartimento di Scienze della Terra Università Sapienza istituto di Geologia Ambientale e Geoingegneria CNR istituto Nazionale di Geofisica e Vulcanologia

We propose that the brittle-ductile transition （BDT） controls the seismic cycle. In particular, the movements detected by space geodesy record the steady state deformation in the ductile lower crust, whereas the stick-slip behavior of the brittle upper crust is constrained by its larger friction. GPS data allow analyzing the strain rate along active plate boundaries. In all tectonic settings, we propose that earthquakes primarily occur along active fault segments characterized by relative minima of strain rate, segments which are locked or slowly creeping. We discuss regional examples where large earthquakes happened in areas of relative low strain rate. Regardless the tectonic style, the interseismic stress and strain pattern inverts during the coseismic stage. Where a dilated band formed during the interseismic stage, this will be shortened at the coseismic stage, and vice-versa what was previously shortened, it will be dilated. The interseismic energy accumulation and the coseismic expenditure rather depend on the tectonic setting （extensional, contractional, or strike-slip）. The gravitational potential energy dominates along normal faults, whereas the elastic energy prevails for thrust earthquakes and performs work against the gravity force. The energy budget in strike-slip tectonic setting is also primarily due elastic energy. Therefore, precursors may be different as a function of the tectonic setting. In this model, with a given displacement, the magnitude of an earthquake results from the coseismic slip of the deformed volume above the BDT rather than only on the fault length, and it also depends on the fault kinematics.

关键词： Earthquake generation mode Strain rate Brittle-ductile transition Earthquake energy

Characterisation of Photocathodes Based on Pb Thin Film Deposited by UV Pulsed Laser Ablation

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Journal of Materials Science & Technology 2014年第1期30卷 37-40页

作者： Francisco Gontad Antonella Lorusso Giancarlo Gatti Massimo Ferrario Laura Gioia Passione Luana Persano Nicola Lovergine Alessio Perrone istituto Nazionale di Fisica Nucleare e Università del Salento Università del Salento Dipartimento di Matematica e Fisica "E.De Giorgi" Laboratori Nazionali di Frascati Istituto Nazionale di Fisica Nucleare Center for Biomolecular Nanotechnologies Istituto Italiano di Tecnologia dipartimento di Ingegneria dell'Innovazione Università del Salento National Nanotechnology Laboratory(NNL)

This work deals with the deposition of lead （Pb） thin films by the UV pulsed laser ablation technique, for their further use as photocathode devices in superconducting radio frequency guns. Scanning electron microscopy and atomic force microscopy analyses were performed to study the morphological features of Pb thin films deposited on Si （100） and Nb substrates. The films showed a granular structure with a nearly fully covered surface only for that one deposited on Nb substrate. X-ray diffraction measurements indicate the growth of polycrystalline Pb thin films with a preferential orientation along （111） planes. Results of the photoemission performance of Pb thin film deposited on Nb substrate showed a very encouraging average value of quantum efficiency of 6 x 10-5 through a single-photon absorption process, promoting further studies in the realisation of Pb photocathodes by this technique.

关键词： Pulsed laser deposition Lead thin film Metallic photocathodes Quantum efficiency

High-speed flow of interacting organic polaritons

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Light(Science & Applications) 2016年第1期5卷 235-240页

作者： Giovanni Lerario Dario Ballarini Antonio Fieramosca Alessandro Cannavale Armando Genco Federica Mangione Salvatore Gambino Lorenzo Dominici Milena De Giorgi Giuseppe Gigli Daniele Sanvitto cnr NANOTEC-istituto di Nanotecnologia Via Monteroni73100 LecceItaly dipartimento di matematica e fisica‘Ennio De Giorgi’ Universitàdel Salento73100 LecceItaly

The strong coupling of an excitonic transition with an electromagnetic mode results in composite quasi-particles called exciton polaritons,which have been shown to combine the best properties of their individual components in semiconductor ***,the physics and applications of polariton flows in organic materials and at room temperature are still unexplored because of the poor photon confinement in such ***,we demonstrate that polaritons formed by the hybridization of organic excitons with a Bloch surface wave are able to propagate for hundreds of microns showing remarkable third-order nonlinear interactions upon high injection *** findings pave the way for the study of organic nonlinear light–matter fluxes and for a technologically promising route of the realization of dissipation-less on-chip polariton devices operating at room temperature.

关键词： optical nonlinearity organic materials polaritons surface waves 2D optics

Planarized THz quantum cascade lasers for broadband coherent photonics

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Light(Science & Applications) 2022年第12期11卷 3098-3108页

作者： Urban Senica Andres Forrer Tudor Olariu Paolo Micheletti Sara Cibella Guido Torrioli Mattias Beck Jerome Faist Giacomo Scalari Quantum Optoelectronics Group Institute of Quantum ElectronicsETH Zurich8093 ZürichSwitzerland istituto di Fotonica e Nanotecnologie CNRVia del Fosso del Cavaliere 10000133 RomeItaly

Recently,there has been a growing interest in integrated THz photonics for various applications in communications,spectroscopy and *** present a new integrated photonic platform based on active and passive elements integrated in a double-metal,high-confinement waveguide layout planarized with a low-loss *** extended top metallization keeps waveguide losses low while improving dispersion,thermal and RF properties,as it enables to decouple the design of THz and microwave ***-running on-chip quantum cascade laser combs spanning 800 GHz,harmonic states with over 1.1 THz bandwidth and RF-injected broadband incoherent states spanning over nearly 1.6 THz are observed using a homogeneous quantum-cascade active *** a strong external RF drive,actively mode-locked pulses as short as 4.4 ps can be produced,as measured by *** demonstrate as well passive waveguides with low insertion loss,enabling the tuning of the laser cavity boundary conditions and the cointegration of active and passive elements on the same THz photonic chip.

关键词： waveguide passive tuning

Post-synthesis phase and shape evolution of CsPbBr3 colloidal nanocrystals: The role of ligands

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Nano Research 2019年第5期12卷 1155-1166页

作者： Elisabetta Fanizza Francesca Cascella Davide Altamura Cinzia Giannini Annamaria Panniello Leonardo Triggiani Francesca Panzarea Nicoletta Depalo Roberto Grisorio Gian Paolo Suranna Angela Agostiano M.Lucia Curri Marinella Striccoli dipartimento di Chimica Università degli Studi di Bari "A.Moro"Via Orabona 470126 BariItaly cnr-istituto per i Processi Chimico Fisici S.S.BariVia Orabona470126 BariItaly cnr-istituto di Cristallografia Via Amendola122/O70126 BariItaly ydipartimento di Ingegneria Civile Ambientaledel TerritorioEdile e di Chimica(DICATECh)Politecnico di BariVia Orabona 470125Italy cnr-NANOTEC-istituto di Nanotecnologia Via Monteroni 73100 LecceItaly

The surface chemistry of colloidal cesium lead bromide (CsPbBr3) nanocrystals is decisive in determining the stability and the final morphology of this class of materials,characterized by ionic structure and a high defect tolerance ***,the high sensitivity of purified colloidal nanocubes of CsPbBr3 to diverse environmental condition (solvent dilution,ageing,ligands post synthetic treatment) in ambient atmosphere is investigated by means of a comprehensive morphological (electron microscopy),structural (θ/2θ X-ray diffraction (XRD) and grazing incidence wide angle scattering (GIWAXS)),and spectroscopic chemical (1H nuclear magnetic resonance (NMR),nuclear Overhauser effect spectroscopy (NOESY),absorption and emission spectroscopy) *** aging and solvent dilution contribute to modify the nanocrystal morphology,due to a modification of the ligand ***,we establish the ability of aliphatic carboxylic acids and aikyl amines ligands to induce,even in a post preparative process at room temperature,structural,morphological and spectroscopic *** post synthesis alkyl amine addition,in particular of oleyl amine and octyl amine,the highly green emitting CsPbBr3 nanocubes effectively tum into one-dimensional (1 D) thin tetragonal nanowires or lead halide deficient rhombohedral zero-dimensional (0D) Cs4PbBr6 structures with a complete loss of *** addition of an alkyl carboxylic acid,as oleic and nonanoic acid,produces the transformation of nanocubes into still emitting orthorombic two-dimensional (2D) *** acid/base equilibrium between the native and added ligands,the edsorbed/free ligands dynamic in solution and the ligand solubility in non-polar solvent contribute to render CsPbBr3 particularly sensitive to environmental and processing conditions and,therefore prone to undergo to structural,morphological and,hence spectroscopic,transformations.

关键词： lead halide perovskite nanocrystals surface chemistry ligands equilibria long term stability

Changes in cellular mechanical properties during onset or progression of colorectal cancer

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World Journal of Gastroenterology 2016年第32期22卷 7203-7214页

作者： Gabriele Ciasca Massimiliano Papi Eleonora Minelli Valentina Palmieri Marco De Spirito istituto di Fisica Università Cattolica del Sacro Cuore

Colorectal cancer(CRC) development represents a multistep process starting with specific mutations that affect proto-oncogenes and tumour suppressor *** mutations confer a selective growth advantage to colonic epithelial cells that form first dysplastic crypts, and then malignant tumours and metastases. All these steps are accompanied by deep mechanical changes at the cellular and the tissue level. A growing consensus is emerging that such modifications are not merely a byproduct of the malignant progression, but they could play a relevant role in the cancer onset and accelerate its progression. In this review, we focus on recent studies investigating the role of the biomechanical signals in the initiation and the development of CRC. We show that mechanical cues might contribute to early phases of the tumour initiation by controlling the Wnt pathway, one of most important regulators of cell proliferation in various systems. We highlight how physical stimuli may be involved in the differentiation of non-invasive cells into metastatic variants and how metastatic cells modify their mechanical properties, both stiffness and adhesion, to survive the mechanical stress associated with intravasation, circulation and extravasation. A deep comprehension of these mechanical modifications may help scientist to define novel molecular targets for the cure of CRC.

关键词： Colorectal cancer Biomechanics Pressure Mechanical signalling Atomic force microscopy Wnt

Cancer stem cells in colorectal cancer from pathogenesis to therapy: Controversies and perspectives

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World Journal of Gastroenterology 2014年第4期20卷 923-942页

作者： Caterina Fanali Donatella Lucchetti Marisa Farina Maddalena Corbi Valerio Cufino Achille Cittadini Alessandro Sgambato istituto di Patologia Generale Università Cattolica del Sacro Cuore

Colorectal cancer remains one of the most common and lethal malignancies worldwide despite the use of various therapeutic strategies. A better understanding of the mechanisms responsible for tumor initiation and progression is essential for the development of novel, more powerful therapies. The traditional, so-called “stochastic model” of tumor development, which assumes that each cancer cell is tumorigenic, has been deeply challenged during the past decade by the identification of cancer stem cells (CSCs), a biologically distinct subset of cells within the bulk of tumor mass. This discovery led to the development of the hierarchical model of tumorigenesis which assumes that only CSCs have the ability to initiate tumor growth, both at primary and metastatic sites. This model implies that the elimination of all CSCs is fundamental to eradicate tumors and that failure to do so might be responsible for the occurrence of relapses and/or metastases frequently observed in the clinical management of colorectal cancer patients. Identification and isolation of CSCs is essential for a better understanding of their role in the tumorigenetic process and for the development of CSC-specific therapies. Several methods have been used for this purpose and many efforts have been focused on the identification of specific CSC-surface markers. This review provides an overview of the proposed roles of CSC in human colorectal tumorigenesis focusing on the most important molecules identified as CSC-specific markers in colorectal cancer and on the potential strategies for the development of CSC-targeted therapy.

关键词： Colorectal cancer Cancer stem cells Tumorigenesis Cancer therapy Prognostic marker

In vitro Effect of dithiocarbamate Pesticides and of CaNa_2EDTA on Human Serum Dopamine-β-hydroxylase

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Biomedical and Environmental Sciences 1995年第2期8卷 114-121页

作者： PAOLA DE PARIS AND STEFANO CAROLdi(istituto di Medicina del Lavoro, Universita’ di Padova, Padova, Italy)(Send correspondence to: Dr. Stefano Caroldi. istituto di Medicina del Lavoro, Via Facciolati 71,I-35127, Padova, Italy. Tel: 3949-8216652, Fax: 3949- istituto di Medicina del Lavoro Università di Padova Italy.

Serum dopamine-β-hydroxylase (DBH) inhibition has been reported in lead workers treated with CaNa2EDTA and in alcoholic patients repeatedly treated with the alcohol aversive drug disulfiram. The mechanism of inhibition involves Cu-chelation at the active site of DBH. The effect of CaNa2EDTA and disulfiram on serum DBH has been compared to the effect of dithiocarbamate pesticides in vitro for the possible use of serum DBH determination for the biological monitoring of workers exposed to these *** dithiocarbamates inhibit human serum DBH at micromoIar concentrations (range of I50, 0.027-1.6 μmol/L). The inhibitory potency increased from methyl- and dimethyl dithiocarbamates to diethyl dithiocarbamates up to the most potent ethylene bisdithiocarbamates. The I50 of *** was 3.8 mol/L, higher than those of dithiocarbamates. Copper addition to the test system rcactivated at stoichiometric concentrations dithiocarbamaie-inhibited DBH indicating that both base line values and percent of inhibition can be calculated in a single blood sample. Results suggest that serum DBH determination couId be useful in case of acute poisoning involving high doses of dithiocarbamate pesticides

关键词： EDTA 络合试剂 hydroxylase