Manipulating quantum Hall edge channels in graphene through Scanning Gate Microscopy

We show evidence of the backscattering of quantum Hall edge channels in a narrow graphene Hall bar, induced by the gating effect of the conducting tip of a Scanning Gate Microscope, which we can position with nanometer precision. We show full control over the edge channels and are able, due to the spatial variation of the tip potential, to separate co-propagating edge channels in the Hall bar, creating junctions between regions of different charge carrier density, that have not been observed in devices based on top- or split-gates. The solution of the corresponding quantum scattering problem is presented to substantiate these results, and possible follow-up experiments are discussed.Comment: 10 pages, 12 figure

Low-temperature quantum transport in CVD-grown single crystal graphene

Chemical vapor deposition (CVD) has been proposed for large-scale graphene synthesis for practical applications. However, the inferior electronic properties of CVD graphene are one of the key problems to be solved. In this study, we present a detailed study on the electronic properties of high-quality single crystal monolayer graphene. The graphene is grown by CVD on copper using a cold-wall reactor and then transferred to Si/SiO2. Our low-temperature magneto-transport data demonstrate that the characteristics of the measured single-crystal CVD graphene samples are superior to those of polycrystalline graphene and have a quality which is comparable to that of exfoliated graphene on Si/SiO2. The Dirac point in our best samples is located at back-gate voltages of less than 10V, and their mobility can reach 11000 cm2/Vs. More than 12 flat and discernible half-integer quantum Hall plateaus have been observed in high magnetic field on both the electron and hole side of the Dirac point. At low magnetic field, the magnetoresistance shows a clear weak localization peak. Using the theory of McCann et al., we find that the inelastic scattering length is larger than 1 {\mu}m in these samples even at the charge neutrality point

Low-temperature quantum transport in CVD-grown single crystal graphene

Chemical vapor deposition (CVD) is typically used for large-scale graphene synthesis for practical applications. However, the inferior electronic properties of CVD graphene are one of the key problems to be solved. Therefore, we present a detailed study on the electronic properties of high-quality single-crystal monolayer graphene. The graphene is grown via CVD on copper, by using a cold-wall reactor, and then transferred to Si/SiO2. Our low-temperature magneto-transport data demonstrate that the characteristics of the single-crystal CVD graphene samples are superior to those of polycrystalline graphene and have a quality which is comparable to that of exfoliated graphene on Si/SiO2. The Dirac point in our best samples occurs at back-gate voltages lower than 10 V, and a maximum mobility of 11,000 cm2/(V·s) is attained. More than 12 flat and discernible half-integer quantum Hall plateaus occur under a high magnetic field on both the electron and hole sides of the Dirac point. At a low magnetic field, the magnetoresistance exhibits a weak localization peak. Using the theory of McCann et al., we obtain inelastic scattering lengths of >1 µm, even at the charge neutrality point of the samples

Phenolic content and antioxidant activity of einkorn and emmer sprouts and wheatgrass obtained under different radiation wavelengths

Abstract Sprouted seeds represent intriguing ready-to-eat micro-scale vegetables for the healthy food market, since they are tasty and rich in bioactive compounds. However, sprouts have been recently proposed as a source for the extraction and purification of several phytochemicals to be used in food supplementation or pharmaceutics. Recently, there has been an industrialization of sprout production, carried out indoor, often with use of artificial light, which have implications on biomass yield and composition, and on energetic and economic costs. This work investigates the effects of different radiation wavelengths from light emitting diodes (LED) on free and bound phenolics and antioxidant activity of sprouts and wheatgrass of einkorn (Triticum monococcum L. ssp. monococcum) and emmer ([(Triticum turgidum L. spp. dicoccum, (Schrank ex Schubler) Thell.)]). After 3 days of grain incubation in the dark, three light treatments were applied, labelled as BLUE (447 and 470 nm), RED (627 and 655 nm), and SUN (447, 470, 505, 530, 590, 627, 655 nm), for a same total photon flux density (PFD) of 200 μmol m−2 s−1. Sprouts were harvested at 5 days after sowing (DAS) and wheatgrass at 9 DAS. The effect of light was generally not significant for sprouts, much greater and species-specific for wheatgrass: BLUE in einkorn and RED in emmer generally increased free and total content of polyphenol (PC), tannins (TC), flavonoid (FC) and phenolic acids (PAs). The antioxidant activity was increased by BLUE in einkorn and decreased by RED in both species. BLUE and RED resulted energy saving compared to SUN

A model of anti-angiogenesis: differential transcriptosome profiling of microvascular endothelial cells from diffuse systemic sclerosis patients

The objective of this work was to identify genes involved in impaired angiogenesis by comparing the transcriptosomes of microvascular endothelial cells from normal subjects and patients affected by systemic sclerosis (SSc), as a unique human model disease characterized by insufficient angiogenesis. Total RNAs, prepared from skin endothelial cells of clinically healthy subjects and SSc patients affected by the diffuse form of the disease, were pooled, labeled with fluorochromes, and hybridized to 14,000 70 mer oligonucleotide microarrays. Genes were analyzed based on gene expression levels and categorized into different functional groups based on the description of the Gene Ontology (GO) consortium to identify statistically significant terms. Quantitative PCR was used to validate the array results. After data processing and application of the filtering criteria, the analyzable features numbered 6,724. About 3% of analyzable transcripts (199) were differentially expressed, 141 more abundantly and 58 less abundantly in SSc endothelial cells. Surprisingly, SSc endothelial cells over-express pro-angiogenic transcripts, but also show up-regulation of genes exerting a powerful negative control, and down-regulation of genes critical to cell migration and extracellular matrix-cytoskeleton coupling, all alterations that provide an impediment to correct angiogenesis. We also identified transcripts controlling haemostasis, inflammation, stimulus transduction, transcription, protein synthesis, and genome organization. An up-regulation of transcripts related to protein degradation and ubiquitination was observed in SSc endothelial cells. We have validated data on the main anti-angiogenesis-related genes by RT-PCR, western blotting, in vitro angiogenesis and immunohistochemistry. These observations indicate that microvascular endothelial cells of patients with SSc show abnormalities in a variety of genes that are able to account for defective angiogenesis

Benda-BEAM High-Dose Therapy Prior to Auto-SCT is Effective in Resistant/Relapsed DLBCL

Abstract Background: The most important drawback of clinical trials of high-dose therapy (HDT) followed by autologous stem cell transplant (ASCT) in lymphomas is the high heterogeneity of histological entities. Therefore, the statistical power is reduced, and data are not conclusive. We previously demonstrated the safety of a new conditioning regimen with bendamustine, etoposide, cytarabine, and melphalan (BeEAM) prior to ASCT in resistant/relapsed lymphoma patients. This combination of drugs was able to induce a high CR rate in a population that did not have an opportunity of being cured with other therapies. However, that study enrolled both Hodgkin and non-Hodgkin lymphoma patients. Aims: We designed a phase II study to evaluate the efficacy of the BeEAM conditioning in resistant/relapsed diffuse large B-cell non-Hodgkin lymphoma (DLBCL) patients. Patients and methods: The study was registered at European Union Drug Regulating Authorities Clinical Trials (EudraCT) N. 2011-001246-14. Until now, 61 patients (median age 54 years, range 19-69) with resistant/relapsed DLBCL were enrolled. The primary end-point of the study is to evaluate the 1-year complete remission rate. Results: Briefly, 46/61 patients had advanced stage disease (III-IV); 20 were primary refractory and 41 had relapsed after a median number of 2 lines of therapy (range: 1-3). Twenty-one patients had 1 or more relevant comorbidities (range: 1- 5). 30 patients were in II or subsequent CR after salvage therapy, whereas 27 were in PR and 4 had stable or progressive disease. A median number of 5.72x106 CD34+/kg cells (range 2.21-10.60) collected from peripheral blood was reinfused to patients. All patients engrafted, with a median time to ANC>0.5x109/l of 10 days. Median times to achieve a platelet count >20x109/l and >50x109/l were 12 and 17 days respectively. Twenty-two out of 61 patients presented a fever of unknown origin (36%), whereas 24 patients (39%) presented a clinically documented infection. All patients received G-CSF after transplant for a median time of 8 days (range: 8-13). One patient died due to an incomplete hematological recovery after transplant, producing an overall transplant related mortality of 2.7%. Fifty-seven patients are evaluable for response: 48/57 (84%) obtained a CR, 3/57 (5%) a PR, whereas 6/57 (11%) did not respond to therapy. After a median follow-up of 10.5 months after transplant (range 3-37), 6/57 (11%) patients were refractory, 12/57 (21%) relapsed and 39/57 (68%) are still alive, in continuous CR. Conclusion: Our clinical trial was designed to closely resemble real-world treatment for these patients. During the study, we transplanted a similar proportion of the patients that would have received ASCT in a real-world scenario. While we cannot make sound comparisons without head-to-head trials, results from previous studies using HDT regimens in DLCBL have not been as encouraging as ours. Accordingly, our data preliminary provide the evidence that the Benda-BEAM regimen is safe and has promising high efficacy in resistant-relapsed aggressive DLBCL patients. Acknowledgments: The study was supported in part by AIL Pesaro Onlus. Mundipharma Italy is grateful acknowledged for providing Bendamustine free of charge. Disclosures Patriarca: Janssen-Cilag, Celgene, Merck Sharp & Dohme: Honoraria. Zinzani:Gilead: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; J&J: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees

Impact of Smoking Status on Mortality in STEMI Patients Undergoing Mechanical Reperfusion for STEMI : Insights from the ISACS–STEMI COVID-19 Registry

The so-called “smoking paradox”, conditioning lower mortality in smokers among STEMI patients, has seldom been addressed in the settings of modern primary PCI protocols. The ISACS– STEMI COVID-19 is a large-scale retrospective multicenter registry addressing in-hospital mortality, reperfusion, and 30-day mortality among primary PCI patients in the era of the COVID-19 pandemic. Among the 16,083 STEMI patients, 6819 (42.3%) patients were active smokers, 2099 (13.1%) previous smokers, and 7165 (44.6%) non-smokers. Despite the impaired preprocedural recanalization (p < 0.001), active smokers had a significantly better postprocedural TIMI flow compared with nonsmokers (p < 0.001); this was confirmed after adjustment for all baseline and procedural confounders, and the propensity score. Active smokers had a significantly lower in-hospital (p < 0.001) and 30-day (p < 0.001) mortality compared with non-smokers and previous smokers; this was confirmed after adjustment for all baseline and procedural confounders, and the propensity score. In conclusion, in our population, active smoking was significantly associated with improved epicardial recanalization and lower in-hospital and 30-day mortality compared with previous and non-smoking histor

Impact of chronic obstructive pulmonary disease on short-term outcome in patients with ST-elevation myocardial infarction during COVID-19 pandemic: insights from the international multicenter ISACS-STEMI registry

Background Chronic obstructive pulmonary disease (COPD) is projected to become the third cause of mortality worldwide. COPD shares several pathophysiological mechanisms with cardiovascular disease, especially atherosclerosis. However, no definite answers are available on the prognostic role of COPD in the setting of ST elevation myocardial infarction (STEMI), especially during COVID-19 pandemic, among patients undergoing primary angioplasty, that is therefore the aim of the current study. Methods In the ISACS-STEMI COVID-19 registry we included retrospectively patients with STEMI treated with primary percutaneous coronary intervention (PCI) between March and June of 2019 and 2020 from 109 high-volume primary PCI centers in 4 continents. Results A total of 15,686 patients were included in this analysis. Of them, 810 (5.2%) subjects had a COPD diagnosis. They were more often elderly and with a more pronounced cardiovascular risk profile. No preminent procedural dissimilarities were noticed except for a lower proportion of dual antiplatelet therapy at discharge among COPD patients (98.9% vs. 98.1%, P = 0.038). With regards to short-term fatal outcomes, both in-hospital and 30-days mortality occurred more frequently among COPD patients, similarly in pre-COVID-19 and COVID-19 era. However, after adjustment for main baseline differences, COPD did not result as independent predictor for in-hospital death (adjusted OR [95% CI] = 0.913[0.658-1.266], P = 0.585) nor for 30-days mortality (adjusted OR [95% CI] = 0.850 [0.620-1.164], P = 0.310). No significant differences were detected in terms of SARS-CoV-2 positivity between the two groups. Conclusion This is one of the largest studies investigating characteristics and outcome of COPD patients with STEMI undergoing primary angioplasty, especially during COVID pandemic. COPD was associated with significantly higher rates of in-hospital and 30-days mortality. However, this association disappeared after adjustment for baseline characteristics. Furthermore, COPD did not significantly affect SARS-CoV-2 positivity. Trial registration number: NCT 04412655 (2nd June 2020)