Suppression of stochastic fluctuations of suspended nanowires by temperature-induced single-electron tunnelling

We investigate theoretically the electromechanical properties of freely suspended nanowires that are in tunnelling contact with the tip of a scanning tunnelling microscope (STM) and two supporting metallic leads. The aim of our analysis is to characterize the fluctuations of the dynamical variables of the nanowire when a temperature drop is mantained between the STM tip and the leads, which are all assumed to be electrically grounded. By solving a quantum master equation that describes the coupled dynamics of electronic and mechanical degrees of freedom we find that the stationary state of the mechanical oscillator has a Gaussian character, but that the amplitude of its root-mean square center-of-mass fluctuations is smaller than would be expected if the system were coupled only to the leads at thermal equilibrium.Comment: Published versio

Sepsis Team Organizational Model to Decrease Mortality for Intra-Abdominal Infections: Is Antibiotic Stewardship Enough?

Introduction. Sepsis is an overwhelming reaction to infection with significant morbidity, requiring urgent interventions in order to improve outcomes. The 2016 Sepsis-3 guidelines modified the previous definitions of sepsis and septic shock, and proposed some specific diagnostic and therapeutic measures to define the use of fluid resuscitation and antibiotics. However, some open issues still exist. Methods. A literature research was performed on PubMed and Cochrane using the terms “sepsis” AND “intra-abdominal infections” AND (“antibiotic therapy” OR “antibiotic treatment”). The inclusion criteria were management of intra-abdominal infection (IAI) and effects of antibiotic stewardships programs (ASP) on the outcome of the patients. Discussion. Sepsis-3 definitions represent an added value in the understanding of sepsis mechanisms and in the management of the disease. However, some questions are still open, such as the need for an early identification of sepsis. Sepsis management in the context of IAI is particularly challenging and a prompt diagnosis is essential in order to perform a quick treatment (source control and antibiotic treatment). Antibiotic empirical therapy should be based on the kind of infection (community or hospital acquired), local resistances, and patient’s characteristic and comorbidities, and should be adjusted or de-escalated as soon as microbiological information is available. Antibiotic Stewardship Programs (ASP) have demonstrated to improve antimicrobial utilization with reduction of infections, emergence of multi-drug resistant bacteria, and costs. Surgeons should not be alone in the management of IAI but ideally inserted in a sepsis team together with anaesthesiologists, medical physicians, pharmacists, and infectious diseases specialists, meeting periodically to reassess the response to the treatment. Conclusion. The cornerstones of sepsis management are accurate diagnosis, early resuscitation, effective source control, and timely initiation of appropriate antimicrobial therapy. Current evidence shows that optimizing antibiotic use across surgical specialities is imperative to improve outcomes. Ideally every hospital and every emergency surgery department should aim to provide a sepsis team in order to manage IAI

Field emission properties of as-grown multiwalled carbon nanotube films

Multiwalled carbon nanotubes have been produced by ethylene catalytic chemical vapor deposition and used to fabricate thick and dense freestanding films ("buckypapers") by membrane filtering. Field emission properties of buckypapers have been locally studied by means of high vacuum atomic force microscopy with a standard metallic cantilever used as anode to collect electrons emitted from the sample. Buckypapers showed an interesting linear dependence in the Fowler-Nordheim plots demonstrating their suitability as emitters. By precisely tuning the tip-sample distance in the submicron region we found out that the field enhancement factor is not affected by distance variations up to 2um. Finally, the study of current stability showed that the field emission current with intensity of about 3,3*10-5A remains remarkably stable (within 5% fluctuations) for several hours.Comment: 18 pages, 5 figure

Field emission from single and few-layer graphene flakes

We report the observation and characterization of field emission current from individual single- and few-layer graphene flakes laid on a flat SiO2/Si substrate. Measurements were performed in a scanning electron microscope chamber equipped with nanoprobes, used as electrodes to realize local measurements of the field emission current. We achieved field emission currents up to 1 {\mu}A from the flat part of graphene flakes at applied fields of few hundred V/{\mu}m. We found that emission process is stable over a period of several hours and that it is well described by a Fowler-Nordheim model for currents over 5 orders of magnitude

Measurement of ultrashort bi-photon correlation times with an integrated two-colour broadband SU(1,1)-interferometer

The bi-photon correlation time, a measure for the conditional uncertainty in the temporal arrival of two photons from a photon pair source, is a key performance identifier for many quantum spectroscopy applications, with shorter correlation times typically yielding better performance. Furthermore, it provides fundamental insight into the effects of dispersion on the bi-photon state. Here, we retrieve ultrashort bi-photon correlation times of around $100\,\mathrm{fs}$ by measuring simultaneously spectral and temporal interferograms at the output of an SU(1,1) interferometer based on an integrated broadband parametric down-conversion source in a $\mathrm{Ti:LiNbO}_3$ waveguideComment: 8 pages, 5 figure

Mortar FEs on Overlapping Meshes : Application to Magnetodynamics

Abstract The finite element (FE) method is frequently used in magnetodynamics as well suited to treat problems with complex geometries while keeping a simplicity in the implementation. However, some modelisations, as in eddy current (EC) non destructive testing (NDT), present the particularity to have moving parts. A global remeshing can be necessary which causes expensive CPU time. Domain decomposition methods allowing to take into account the movement without having to remesh the whole computational domain. The mortar element method (MEM), a variational non-conforming domain decomposition approach [1] offers attractive advantages in terms of flexibility and accuracy. In its original version for non-overlapping subdomains, the information is transferred through the skeleton of the decomposition by means of a suitable L 2 -projection of the field trace from the master to the slave subdomains. A MEM with overlapping subdomains has been proposed to coupled a global scalar potential defined everywhere in the considered domain and a local vector potential defined only in (possibly moving) conductor

Further progress/developments, on surface/bulk treated Constantan wires, for anomalous heat generation by H2/D2 interaction

In the framework of those studies aimed to analyze anomalous effects (thermal and/or nuclear) due to the interaction among some specific materials (pure and/or alloys) and H2 (or D2), we focused, since 2011, on a specific alloy called Constantan (Cu55-Ni44-Mn1). We selected such material using our own considerations and intuitions and because, according to a scientific paper [1], it has the largest energy value for dissociation of H2 to 2H, i.e. about 3eV. Among others B. Ahern suggested that Ni-Cu-H can be used for heat generation. We improved the preparation procedure of such wire from simple thermal treatments (up to May 2012 [2])to more sophisticated ones, with more tight control of the multilayered (400-700) surface structures. Some of the results were presented at ICCF17, Aug. 2012 [3]. After [3], several groups asked to make their own experiments using such kind of wires ([phi]=200[mu]m, l=100cm) to cross-check (and possibly improve) our results. Some of such Researchers (group of M. Fleischmann Memorial Project; U. Mastromatteo) made public their (positive) results since Dec. 14, 2012 at Ministry of Aeronautics in Rome, Italy. In short, using an (home-made) apparatus integrated with an acquisition system (type PXi) by National Instruments, we made, since September 2012, not mentioning qualitative reconfirmation of previous results, further and unexpected progress and discoveries: a) We developed a new kind of procedure of measurement (about anomalous excess heat) under dynamic vacuum, to avoid the effect of different thermal conductivity, inside the gas cell, due to type of gas and pressure variation: the wire didn't lose, macroscopically, H even at T=600[degrees]C. b) We developed a new, very simple, type of surface coating (2 layers) that is nano-diamandoidslike; c) We observed, at least 2 times, the phenomenon of water splitting due to catalytic effect of surface treated Constantan. Such phenomenon is larger in comparison with what expected just by thermal splitting (wires temperature of about 300-500[degrees]C); d) We observed a very large variation (about a factor 100) of Resistive Thermal Coefficient (RTC) of the wire used (400 layers) as the amount of H (related to the macroscopic value of resistive ratio R/Ro, normalize to empty wire Ro) increased. As example, with "treated" virgin wire (w/o H2) the RTC was about 5*10-6 and increased to6*10-4 when the R/Ro reduced to 0.68; temperature range 20-300[degrees]C. The RTC is larger with D in respect to H. Experiments are in progress also at 77K. e) Overall results are affected by previous operating conditions

Serum klotho concentrations inversely correlate with the severity of nailfold capillaroscopic patterns in patients with systemic sclerosis

Klotho is a transmembrane and soluble glycoprotein that governs vascular integrity. Previous studies have demonstrated reduced serum klotho concentrations in patients with systemic sclerosis (SSc), and it is known that klotho deficiency can impair the healing of digital ulcers related to microvessel damage. The aim of this study was to evaluate the association between serum klotho levels and nailfold capillaroscopic abnormalities in SSc patients. We retrospectively enrolled 54 consecutive patients with SSc diagnosed on the basis of the 2013 EULAR/ACR criteria [11 with diffuse SSc; 47 females; median age 68.0 years (IQ 18); median disease duration 11.0 years (IQ 7)]. Serum klotho concentrations were determined by means of an enzyme-linked immunosorbent assay. On the basis of the 2000 classification of Cutolo et al., 14 patients had normal nailfold capillaroscopic findings, 8 had an early scleroderma pattern, 21 an active scleroderma pattern, and 11 a late scleroderma pattern. The median serum klotho concentration was 0.29 ng/mL (IQ 1). Regression analysis of variation showed an inverse correlation between serum klotho concentrations and the severity of the capillaroscopic pattern (p=0.02; t -2.2284), which was not influenced by concomitant treatment. Logistic regression did not reveal any significant association between the risk of developing digital ulcers and nailfold capillaroscopic patterns, serum klotho levels, or concomitant medications. The presence of avascular areas significantly correlated with calcinosis (p=0.006). In line with previous studies, our findings confirm that klotho plays a role in preventing microvascular damage detected with nailfold capillaroscopy

What do we have to know about PD-L1 expression in prostate cancer? A systematic literature review. part 4: Experimental treatments in pre-clinical studies (cell lines and mouse models)

In prostate cancer (PC), the PD-1/PD-L1 axis regulates various signaling pathways and it is influenced by extracellular factors. Pre-clinical experimental studies investigating the effects of various treatments (alone or combined) may discover how to overcome the immunotherapyresistance in PC-patients. We performed a systematic literature review (PRISMA guidelines) to delineate the landscape of pre-clinical studies (including cell lines and mouse models) that tested treatments with effects on PD-L1 signaling in PC. NF-kB, MEK, JAK, or STAT inhibitors on human/mouse, primary/metastatic PC-cell lines variably down-modulated PD-L1-expression, reducing chemoresistance and tumor cell migration. If PC-cells were co-cultured with NK, CD8+ Tcells or CAR-T cells, the immune cell cytotoxicity increased when PD-L1 was downregulated (opposite effects for PD-L1 upregulation). In mouse models, radiotherapy, CDK4/6-inhibitors, and RB deletion induced PD-L1-upregulation, causing PC-immune-evasion. Epigenetic drugs may reduce PD-L1 expression. In some PC experimental models, blocking only the PD-1/PD-L1 pathway had limited efficacy in reducing the tumor growth. Anti-tumor effects could be increased by combining the PD-1/PD-L1 blockade with other approaches (inhibitors of tyrosine kinase, PI3K/mTOR or JAK/STAT3 pathways, p300/CBP; anti-RANKL and/or anti-CTLA-4 antibodies; cytokines; nitroxoline; DNA/cell vaccines; radiotherapy/Radium-223)