Non-linear Coulomb blockade microscopy of a correlated one-dimensional quantum dot

We evaluate the chemical potential of a one-dimensional quantum dot, coupled to an atomic force microscope tip. The dot is described within the Luttinger liquid framework and the conductance peaks positions as a function of the tip location are calculated in the linear and non-linear transport regimes for an arbitrary number of particles. The differences between the chemical potential oscillations induced by Friedel and Wigner terms are carefully analyzed in the whole range of interaction strength. It is shown that Friedel oscillations, differently from the Wigner ones, are sensitive probes to detect excited spin states and collective spin density waves involved in the transport.Comment: 4 figure

Effect of recombinant human nerve growth factor eye drops in patients with dry eye: a phase IIa, open label, multiple-dose study

Background: Dry eye disease (DED) affects more than 14% of the elderly population causing decrease of quality of life, high costs and vision impairment. Current treatments for DED aim at lubricating and controlling inflammation of the ocular surface. Development of novel therapies targeting different pathogenic mechanisms is sought-after. The aim of this study is to evaluate safety and efficacy of recombinant human nerve growth factor (rhNGF) eye drops in patients with DED. Methods: Forty consecutive patients with moderate to severe DED were included in a phase IIa, prospective, open label, multiple-dose, clinical trial to receive rhNGF eye drops at 20 μg/mL (Group 1: G1) or at 4 μg/mL (Group 2: G2) concentrations, two times a day in both eyes for 28 days (NCT02101281). The primary outcomes measures were treatment-emerged adverse events (AE), Symptoms Assessment in Dry Eye (SANDE) scale, ocular surface staining and Schirmer test. Results: Of 40 included patients, 39 completed the trial. Both tested rhNGF eye drop concentrations were safe and well tolerated. Twenty-nine patients experienced at least one AE (14 in G1 and 15 in G2), of which 11 had at least 1 related AE (8 in G1 and 3 in G2). Both frequency and severity of DED symptoms and ocular surface damage showed significant improvement in both groups, while tear function improved only in G1. Conclusions: The data of this study indicate that rhNGF eye drops in both doses is safe and effective in improving symptoms and signs of DED. Randomised clinical trials are ongoing to confirm the therapeutic benefit of rhNGF in DED. Trial registration number: NCT02101281

Blocking transport resonances via Kondo entanglement in quantum dots

Many-body entanglement is at the heart of the Kondo effect, which has its hallmark in quantum dots as a zero-bias conductance peak at low temperatures. It signals the emergence of a conducting singlet state formed by a localized dot degree of freedom and conduction electrons. Carbon nanotubes offer the possibility to study the emergence of the Kondo entanglement by tuning many-body correlations with a gate voltage. Here we quantitatively show an undiscovered side of Kondo correlations, which counterintuitively tend to block conduction channels: inelastic cotunneling lines in the magnetospectrum of a carbon nanotube strikingly disappear when tuning the gate voltage. Considering the global \SUT\ $\otimes$ \SUT\ symmetry of a carbon nanotube coupled to leads, we find that only resonances involving flips of the Kramers pseudospins, associated to this symmetry, are observed at temperatures and voltages below the corresponding Kondo scale. Our results demonstrate the robust formation of entangled many-body states with no net pseudospin.Comment: 9 pages, 4 figure

Devenir post-opératoire des patientes opérées au CHUV dans le contexte d’endométriose sévère entre 2011 et 2016

Objectifs : Evaluer les complications opératoires et post-opératoires des chirurgies de l’endométriose sévère au CHUV afin de déterminer les risques liés à cette prise en charge. Méthode : Analyse rétrospective des dossiers de 127 patientes opérées au CHUV de leur endométriose sévère entre 2011 et 2016. Les dossiers contenant une opération en lien avec l’endométriose ont été retenus puis analysés afin de ne garder que ceux concernant une chirurgie d’endométriose sévère, nous donnant un collectif de 127 patientes. Nous avons récolté des informations concernant la localisation des lésions, les gestes opératoires effectués, les complications opératoires et post-opératoires, ainsi que la durée d’hospitalisation. Outcome primaire : Taux de complications (majeures et mineures) intra-opératoires et post-opératoires. Résultats : Dans notre série de 127 patientes, 9 (7%) ont présenté une complication péri-opératoire : 8 mineures (hémorragies, brèches, conversion en laparotomie) et une majeure (lésion d’uretère). Huit patientes (6,3%) ont présenté des complications post-opératoires : 5 mineures (hématome, surcharge liquidienne, collection liquidienne, thrombose des veines ovariennes, phlébite) et 3 majeures (embolie pulmonaire, deux abcès drainés). Le taux de complication majeure s’élève donc à 3,1% (4 patientes). Nous observons une seule conversion en laparotomie et un séjour hospitalier moyen de de 2,8 jours. Discussion et conclusion : Le taux de complication de la chirurgie de l’endométriose sévère au CHUV est comparable aux taux retrouvés dans la littérature. Ces interventions entraînent donc peu de complications mais pouvant s’avérer graves. Nous avons en effet retrouvé quatre complications majeures nécessitant des interventions supplémentaires. Il serait intéressant de déterminer le devenir à plus long terme de ces patientes, notamment l’effet au niveau de la douleur et de la fertilité

Dynamic Effect of Cold-Air Bypass Valve for Compressor Surge Recovery and Prevention in Fuel Cell Gas Turbine Hybrid Systems

A large volume between compressor and turbine is present in fuel cell gas turbine hybrid systems. The substantially larger compressor plenum volume modifies the dynamic behaviour of these systems, increasing the risk of compressor surge during transients and subsequent destruction of both turbomachinery and fuel cell components. Diverting part of the compressor inlet flow directly to the turbine inlet through a cold-air bypass valve, bypassing the fuel cell stack, has been proven to be an effective method to increase the surge margin during normal operation and also to recover the machine from fully developed surge. This study investigates the dynamic effect of different cold-air bypass valve opening/closing procedures, especially steps and ramps changing the valve fractional opening. This analysis was carried out with reference to the Hybrid Performance (Hyper) facility: a hybrid system emulated using hardware and a cyber-physical fuel cell system at the National Energy Technology Laboratory (NETL), U.S. Department of Energy (DOE). Simulations performed on a Matlab\uae-Simulink\uae dynamic model of the system based on Greitzer's theory showed a different behaviour varying the valve fractional opening with steps or ramps. Many experimental tests were performed on the Hyper facility to confirm the trends obtained from the simulations results. From the outcomes of this study, it has been possible to determine how to maximize the surge recovery effect of the cold-air bypass valve opening and to minimize surge related risks during the valve closure

WILSON PLOT METHOD TO OBTAIN NUSSELT NUMBER FOR A PLATE HEAT EXCHANGER

Plate heat exchangers are devices commonly used in industry due to their high efficiency and ease cleaning. Although its first use was in food sector, nowadays this equipment can be found in most industrial segments, like chemistry and oil industry. Due the facility of fabrication, the corrugated gasket plate heat exchanger is amply utilized in those segments, however, its mathematical analysis present non-agreement between the authors, because of the different plate models and operation settings. Thus, the main objective of this work is to study the application of the Wilson-Plot method to analyze the thermal behavior of an elemental plate heat exchanger, and verify if the operation temperature has significant influence in the thermal behavior of the plate heat exchanger

Potential-induced acid-base chemistry of adsorbed species

The pKa of bicarbonate ion adsorbed on the surface of Pt(111), HCO3−(ads), in CO2 -saturated KClO4/HClO4 aqueous solutions has been determined by judicious application of a theoretical model originally proposed by Smith and White (Langmuir 1993, 9 (1), 1–3) to explain voltammetric features found for non-redox active alkyl chain monolayers bearing carboxylic moieties irreversibly bound to gold surfaces. The analysis herein presented relied on and coverages derived from in situ Fourier transform infrared spectroscopy measurements as a function of potential and pH reported by Martinez-Hincapie et al. (J. Phys. Chem. C 2016, 120 (29), 16191–16199), as input parameters, yielding a pKa for HCO3−(ads) of ca. 2.6 ± 0.2. This value is significantly smaller than that of HCO3−(aq) in bulk solutions, a phenomenon associated with the bonding of the species to the electrode surface, a factor that markedly modifies its acid base characteristics.This work was supported by a grant from the National Science Foundation (US) CHE 1808592

Automated detection and characterization of Antarctic basal units using radar sounding data: demonstration in Institute Ice Stream, West Antarctica

Basal units – visibly distinct englacial structures near the ice-bed interface – warrant investigation for a number of reasons. Many are of unknown composition and origin, characteristics that could provide substantial insight into subglacial processes and ice-sheet history. Their significance, moreover, is not limited to near-bed depths; these units appear to dramatically influence the flow of surrounding ice. In order to enable improved characterization of these features, we develop and apply an algorithm that allows for the automatic detection of basal units. We use a tunable layer-optimized SAR processor to distinguish these structures from the bed, isochronous englacial layers and the ice-sheet surface, presenting a conceptual framework for the use of radio-echo character in the identification of ice-sheet features. We also outline a method by which our processor could be used to place observational constraints on basal units’ configuration, composition and provenance

L’ambiente carsico e l’idrogeologia dei gessi di Sassalbo (MS)

Nel Canale dell’Acqua Torbida (Alta Lunigiana), si trova il maggiore affioramento di evaporiti triassiche della Toscana. Rispetto ai gessi dell’Alta val Secchia (RE), di cui sono il lembo meridionale, appaiono molto meno tettonizzati. L’area carsica, che comprende in prevalenza calcari cavernosi, ha una superficie complessiva di circa 2,2 km2 in cui sono ben rappresentate forme carsiche superficiali, sia macro che micro. Anche i fenomeni carsici sotterranei sembrano essere ben sviluppati: la loro genesi è stata attribuita a periodi di avanzata e arretramento dei ghiacciai durante l’ultimo glaciale. Attualmente nel catasto toscano sono registrate 5 cavità, di cui 4 rilevate. Nell’ambito del Progetto Trias II (studio interdisciplinare svolto dalla Società Speleologica Italiana per conto del Parco Nazionale dell’Appennino Tosco-Emiliano) è stato possibile studiare l’area dal punto di vista morfologico, speleologico e idrochimico, monitorando in continuo alcune delle principali risorgenti carsiche parallelamente ai torrenti cui esse potevano risultare connesse. Nel presente lavoro, dopo breve illustrazione delle morfologie epigee ed ipogee, vengono presentati i risultati del monitoraggio idrologico. Le analisi hanno permesso di evidenziare come in molti casi le acque del carso di Sassalbo siano chimicamente molto simili a quelle del sistema ad ansa ipogea del Tanone della Gacciolina in Alta val di Secchia. Fanno eccezione altre sorgenti, alimentate quasi esclusivamente dalla serie marnoso arenacea e dal macigno, che presentano comportamenti idrodinamici differenti in funzione dei loro specifici bacini di alimentazione.Karst and hydrology of the Sassalbo Gypsa (Massa Carrara – Italy) The largest triassic evaporitic outcrop of Tuscany is located inside the Acqua Torbida creek (Upper Lunigiana). They represent the southernmost and less tectonized part of the Upper Secchia Gypsa (RE). The karst area (some 2,2) consists mostly of limestone (Calcari Cavernosi) with well developed macro – and micro – forms. The underground phenomena are mainly related to the mouventes of glacial tongues during the last Glacial. 5 cavities are presently known and inserted in the Tuscany Cadaster, 4 of which mapped. In the framework of the Trias II Project (an interdisciplinary study sponsored by the Appennino Tosco-Emiliano National Park and performed by the Italian Speleological Society) this area has been investigated from the morphological, speleological, hydrochemical point of view while some of the major springs and related rivers were monitored. In the paper after a short description of the epigean and hypogean forms, the achieved result during the hydrological study are presented. This study evidenced that in many occurrences the behavior of the Sassalbo karst waters is very similar to that of the Tanone della Gacciolina cave in the Upper Secchia Valley. Only a few springs exhibit a different behavior being rather completely fed by the marnoso-arenacea and macigno formations

Microenvironment in neuroblastoma: Isolation and characterization of tumor-derived mesenchymal stromal cells

Background: It has been proposed that mesenchymal stromal cells (MSCs) promote tumor progression by interacting with tumor cells and other stroma cells in the complex network of the tumor microenvironment. We characterized MSCs isolated and expanded from tumor tissues of pediatric patients diagnosed with neuroblastomas (NB-MSCs) to define interactions with the tumor microenvironment. Methods: Specimens were obtained from 7 pediatric patients diagnosed with neuroblastoma (NB). Morphology, immunophenotype, differentiation capacity, proliferative growth, expression of stemness and neural differentiation markers were evaluated. Moreover, the ability of cells to modulate the immune response, i.e. inhibition of phytohemagglutinin (PHA) activated peripheral blood mononuclear cells (PBMCs) and natural killer (NK) cytotoxic function, was examined. Gene expression profiles, known to be related to tumor cell stemness, Wnt pathway activation, epithelial-mesenchymal transition (EMT) and tumor metastasis were also evaluated. Healthy donor bone marrow-derived MSCs (BM-MSC) were employed as controls. Results: NB-MSCs presented the typical MSC morphology and phenotype. They showed a proliferative capacity superimposable to BM-MSCs. Stemness marker expression (Sox2, Nanog, Oct3/4) was comparable to BM-MSCs. NB-MSC in vitro osteogenic and chondrogenic differentiation was similar to BM-MSCs, but NB-MSCs lacked adipogenic differentiation capacity. NB-MSCs reached senescence phases at a median passage of P7 (range, P5-P13). NB-MSCs exhibited greater immunosuppressive capacity on activated T lymphocytes at a 1:2 (MSC: PBMC) ratio compared with BM-MSCs (p = 0.018). NK cytotoxic activity was not influenced by co-culture, either with BM-MSCs or NB-MSCs. Flow-cytometry cell cycle analysis showed that NB-MSCs had an increased number of cells in the G0-G1 phase compared to BM-MSCs. Transcriptomic profiling results indicated that NB-MSCs were enriched with EMT genes compared to BM-MSCs. Conclusions: We characterized the biological features, the immunomodulatory capacity and the gene expression profile of NB-MSCs. The NB-MSC gene expression profile and their functional properties suggest a potential role in promoting tumor escape, invasiveness and metastatic traits of NB cancer cells. A better understanding of the complex mechanisms underlying the interactions between NB cells and NB-derived MSCs should shed new light on potential novel therapeutic approaches