97 research outputs found

    Nanometer-Scale Lateral p–n Junctions in Graphene/α-RuCl3 Heterostructures

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    [EN] The ability to create nanometer-scale lateral p-n junctions is essential for the next generation of two-dimensional (2D) devices. Using the charge-transfer heterostructure graphene/alpha-RuCl3, we realize nanoscale lateral p-n junctions in the vicinity of graphene nanobubbles. Our multipronged experimental approach incorporates scanning tunneling microscopy (STM) and spectroscopy (STS) and scattering-type scanning near-field optical microscopy (s-SNOM) to simultaneously probe the electronic and optical responses of nanobubble p-n junctions. Our STM/STS results reveal that p-n junctions with a band offset of 0.6 eV can be achieved with widths of 3 nm, giving rise to electric fields of order 108 V/m. Concurrent s-SNOM measurements validate a point-scatterer formalism for modeling the interaction of surface plasmon polaritons (SPPs) with nanobubbles. Ab initio density functional theory (DFT) calculations corroborate our experimental data and reveal the dependence of charge transfer on layer separation. Our study provides experimental and conceptual foundations for generating p-n nanojunctions in 2D materials.Research at Columbia University was supported as part of the Energy Frontier Research Center on Programmable Quantum Materials funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award No DE-SC0019443. Plasmonic nano-imaging at Columbia University was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award No DE-SC0018426. J.Z. and A.R. were supported by the European Research Council (ERC-2015-AdG694097), the Cluster of Excellence “Advanced Imaging of Matter” (AIM) EXC 2056-390715994, funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under RTG 2247, Grupos Consolidados (IT1249-19), and SFB925 “Light induced dynamics and control of correlated quantum systems”. J.Z. and A.R. would like to acknowledge Nicolas Tancogne-Dejean and Lede Xian for fruitful discussions and also acknowledge support by the Max Planck Institute-New York City Center for Non-Equilibrium Quantum Phenomena. The Flatiron Institute is a division of the Simons Foundation. J.Z. acknowledges funding received from the European Union Horizon 2020 research and innovation programme under Marie SkƂodowska-Curie Grant Agreement 886291 (PeSD-NeSL). STM support was provided by the National Science Foundation via Grant DMR-2004691. C.R.-V. acknowledges funding from the European Union Horizon 2020 research and innovation programme under the Marie SkƂodowska-Curie Grant Agreement 844271. D.G.M. acknowledges support from the Gordon and Betty Moore Foundation’s EPiQS Initiative, Grant GBMF9069. J.Q.Y. was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. S.E.N. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Division of Scientific User Facilities. Work at University of Tennessee was supported by NSF Grant 180896

    Cardiogenic shock following administration of propofol and fentanyl in a healthy woman: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Cardiogenic shock is very uncommon in healthy people. The differential diagnosis for patients with acute heart failure in previously healthy hearts includes acute myocardial infarction and myocarditis. However, many drugs can also depress myocardial function. Propofol and fentanyl are frequently used during different medical procedures. The cardiovascular depressive effect of both drugs has been well established, but the development of cardiogenic shock is very rare when these agents are used.</p> <p>Case presentation</p> <p>After a minor surgical intervention, a 32-year-old Caucasian woman with no significant medical history went into sudden hemodynamic deterioration due to acute heart failure. An urgent echocardiogram showed severe biventricular dysfunction and an estimated left ventricular ejection fraction of 20%. Extracorporeal life support and mechanical ventilation were required. Five days later her ventricular function had fully recovered, which allowed the progressive withdrawal of medical treatment. Prior to her hospital discharge, cardiac MRI showed neither edema nor pathological deposits on the delayed contrast enhancement sequences. At her six-month follow-up examination, the patient was asymptomatic and did not require treatment.</p> <p>Conclusion</p> <p>Although there are many causes of cardiogenic shock, the presence of abrupt hemodynamic deterioration and the absence of a clear cause could be related to the use of propofol and fentanyl.</p

    Citicoline induces angiogenesis improving survival of vascular/human brain microvessel endothelial cells through pathways involving ERK1/2 and insulin receptor substrate-1.

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    BACKGROUND: Citicoline is one of the neuroprotective agents that have been used as a therapy in stroke patients. There is limited published data describing the mechanisms through which it acts. METHODS: We used in vitro angiogenesis assays: migration, proliferation, differentiation into tube-like structures in Matrigelℱ and spheroid development assays in human brain microvessel endothelial cells (hCMEC/D3). Western blotting was performed on protein extraction from hCMEC/D3 stimulated with citicoline. An analysis of citicoline signalling pathways was previously studied using a Kinexus phospho-protein screening array. A staurosporin/calcium ionophore-induced apoptosis assay was performed by seeding hCMEC/D3 on to glass coverslips in serum poor medium. In a pilot in vivo study, transient MCAO in rats was carried out with and without citicoline treatment (1000 mg/Kg) applied at the time of occlusion and subsequently every 3 days until euthanasia (21 days). Vascularity of the stroke-affected regions was examined by immunohistochemistry. RESULTS: Citicoline presented no mitogenic and chemotactic effects on hCMEC/D3; however, it significantly increased wound recovery, the formation of tube-like structures in Matrigelℱ and enhanced spheroid development and sprouting. Citicoline induced the expression of phospho-extracellular-signal regulated kinase (ERK)-1/2. Kinexus assays showed an over-expression of insulin receptor substrate-1 (IRS-1). Knock-down of IRS-1 with targeted siRNA in our hCMEC/D3 inhibited the pro-angiogenic effects of citicoline. The percentage of surviving cells was higher in the presence of citicoline. Citicoline treatment significantly increased the numbers of new, active CD105-positive microvessels following MCAO. CONCLUSIONS: The findings demonstrate both a pro-angiogenic and protective effect of citicoline on hCMEC/D3 in vitro and following middle cerebral artery occlusion (MCAO) in vivo

    Integration of aqueous (micellar) two-phase systems on the proteins separation

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    A two-step approach combining an aqueous two-phase system (ATPS) and an aqueous micellar two-phase system (AMTPS), both based on the thermo-responsive copolymer Pluronic L-35, is here proposed for the purification of proteins and tested on the sequential separation of three model proteins, cytochrome c, ovalbumin and azocasein. Phase diagrams were established for the ATPS, as well as co-existence curves for the AMTPS. Then, by scanning and choosing the most promising systems, the separation of the three model proteins was performed. The aqueous systems based on Pluronic L-35 and potassium phosphate buffer (pH = 6.6) proved to be the most selective platform to separate the proteins (SAzo/Cyt = 1667; SOva/Cyt = 5.33 e SAzo/Ova = 1676). The consecutive fractionation of these proteins as well as their isolation from the aqueous phases was proposed, envisaging the industrial application of this downstream strategy. The environmental impact of this downstream process was studied, considering the carbon footprint as the final output. The main contribution to the total carbon footprint comes from the ultrafiltration (~ 49%) and the acid precipitation (~ 33%) due to the energy consumption in the centrifugation. The ATPS step contributes to ~ 17% while the AMTPS only accounts for 0.30% of the total carbon footprint.publishe

    Screening of cannabis-related problems among youth: the CPQ-A-S and CAST questionnaires

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    <p>Abstract</p> <p>Background</p> <p>Cannabis use among young people is a significant problem, making particularly necessary validated screening instruments that permit secondary prevention. The purpose of this study was to analyze and compare the psychometric properties of the CAST and CPQ-A-S questionnaires, two screening instruments specifically addressing the youth population.</p> <p>Methods</p> <p>Information was obtained on sociodemographics, frequency of substance use, psychopathological symptoms and cannabis-use problems, and the CPQ-A-S and CAST were applied, as well as an infrequency scale for discarding responses made randomly. The sample was made up of 144 young people aged 16 to 20 that had used cannabis in the last month, of which 71.5% were boys. Mean age of the sample was 17.38 years (SD = 1.16).</p> <p>Results</p> <p>The results show that from the psychometric point of view both the CAST and the CPQ-A-S are good screening instruments.</p> <p>Conclusions</p> <p>The CAST is shorter and presents slightly better internal consistency than the CPQ-A-S. Both instruments show high sensitivity and specificity in the detection of young people dependent on cannabis according to the DSM IV-TR criteria. The CPQ-A-S appears to show greater capacity for detecting psychopathological distress associated with use. Both questionnaires yield significant odds ratios as predictors of frequent cannabis use and of the DSM IV-TR abuse and dependence criteria. In general, the CPQ-A-S emerges as a better predictor than the CAST.</p

    Transcriptional Responses of Resistant and Susceptible Fish Clones to the Bacterial Pathogen Flavobacterium psychrophilum

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    Flavobacterium psychrophilum is a bacterial species that represents one of the most important pathogens for aquaculture worldwide, especially for salmonids. To gain insights into the genetic basis of the natural resistance to F. psychrophilum, we selected homozygous clones of rainbow trout with contrasted susceptibility to the infection. We compared the transcriptional response to the bacteria in the pronephros of a susceptible and a resistant line by micro-array analysis five days after infection. While the basal transcriptome of healthy fish was significantly different in the resistant and susceptible lines, the transcriptome modifications induced by the bacteria involved essentially the same genes and pathways. The response to F. psychrophilum involved antimicrobial peptides, complement, and a number of enzymes and chemokines. The matrix metalloproteases mmp9 and mmp13 were among the most highly induced genes in both genetic backgrounds. Key genes of both pro- and anti-inflammatory response such as IL1 and IL10, were up-regulated with a greater magnitude in susceptible animals where the bacterial load was also much higher. While higher resistance to F. psychrophilum does not seem to be based on extensive differences in the orientation of the immune response, several genes including complement C3 showed stronger induction in the resistant fish. They may be important for the variation of susceptibility to the infection

    Ferric carboxymaltose with or without erythropoietin for the prevention of red-cell transfusions in the perioperative period of osteoporotic hip fractures: a randomized contolled trial. The PAHFRAC-01 project

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    Background: Around one third to one half of patients with hip fractures require red-cell pack transfusion. The increasing incidence of hip fracture has also raised the need for this scarce resource. Additionally, red-cell pack transfusions are not without complications which may involve excessive morbidity and mortality. This makes it necessary to develop blood-saving strategies. Our objective was to assess safety, efficacy, and cost-effictveness of combined treatment of i.v. ferric carboxymaltose and erythropoietin (EPOFE arm) versus i.v. ferric carboxymaltose (FE arm) versus a placebo (PLACEBO arm) in reducing the percentage of patients who receive blood transfusions, as well as mortality in the perioperative period of hip fracture intervention. Methods/Design: Multicentric, phase III, randomized, controlled, double blinded, parallel groups clinical trial. Patients > 65 years admitted to hospital with a hip fracture will be eligible to participate. Patients will be treated with either a single dosage of i.v. ferric carboxymaltose of 1 g and subcutaneous erythropoietin (40.000 IU), or i.v. ferric carboxymaltose and subcutaneous placebo, or i.v. placebo and subcutaneous placebo. Follow-up will be performed until 60 days after discharge, assessing transfusion needs, morbidity, mortality, safety, costs, and health-related quality of life. Intention to treat, as well as per protocol, and incremental cost-effectiveness analysis will be performed. The number of recruited patients per arm is set at 102, a total of 306 patients. Discussion: We think that this trial will contribute to the knowledge about the safety and efficacy of ferric carboxymaltose with/without erythropoietin in preventing red-cell pack transfusions in patients with hip fracture. ClinicalTrials.gov identifier: NCT01154491

    Clinical and cost-effectiveness of contingency management for cannabis use in early psychosis: the CIRCLE randomised clinical trial

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    Background Cannabis is the most commonly used illicit substance among people with psychosis. Continued cannabis use following the onset of psychosis is associated with poorer functional and clinical outcomes. However, finding effective ways of intervening has been very challenging. We examined the clinical and cost-effectiveness of adjunctive contingency management (CM), which involves incentives for abstinence from cannabis use, in people with a recent diagnosis of psychosis. Methods CIRCLE was a pragmatic multi-centre randomised controlled trial. Participants were recruited via Early Intervention in Psychosis (EIP) services across the Midlands and South East of England. They had had at last one episode of clinically diagnosed psychosis (affective or non-affective); were aged 18 to 36; reported cannabis use in at least 12 out of the previous 24 weeks; and were not currently receiving treatment for cannabis misuse, or subject to a legal requirement for cannabis testing. Participants were randomised via a secure web-based service 1:1 to either an experimental arm, involving 12 weeks of CM plus a six-session psychoeducation package, or a control arm receiving the psychoeducation package only. The total potential voucher reward in the CM intervention was ÂŁ240. The primary outcome was time to acute psychiatric care, operationalised as admission to an acute mental health service (including community alternatives to admission). Primary outcome data were collected from patient records at 18 months post-consent by assessors masked to allocation. The trial was registered with the ISRCTN registry, number ISRCTN33576045. Results: 551 participants were recruited between June 2012 and April 2016. Primary outcome data were obtained for 272 (98%) in the CM (experimental) group and 259 (95%) in the control group. There was no statistically significant difference in time to acute psychiatric care (the primary outcome) (HR 1.03, 95% CI 0.76, 1.40) between groups. By 18 months, 90 (33%) of participants in the CM group, and 85 (30%) of the control groups had been admitted at least once to an acute psychiatric service. Amongst those who had experienced an acute psychiatric admission, the median time to admission was 196 days (IQR 82, 364) in the CM group and 245 days (IQR 99,382) in the control group. Cost-effectiveness analyses suggest that there is an 81% likelihood that the intervention was cost-effective, mainly resulting from higher mean inpatient costs for the control group compared with the CM group, however the cost difference between groups was not statistically significant. There were 58 adverse events, 27 in the CM group and 31 in the control group. Conclusions Overall, these results suggest that CM is not an effective intervention for improving the time to acute psychiatric admission or reducing cannabis use in psychosis, at least at the level of voucher reward offered

    Adherence to treatment to help quit smoking: effects of task performance and coping with withdrawal symptoms

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    Background: Currently the combined cognitive-behavioral and pharmacological treatment is the best option to quit smoking, although success rates remain moderate. This study aimed to identify predictors of continuous abstinence in an assisted smoking cessation program using combined treatment. In particular, we analyzed the effects of socio-demographic, smoking-, and treatment-related variables. In addition, we analyzed the effect of several risk factors on abstinence, and estimated a model of risk for smoking relapse.Methods: Participants were 125 workers at the University of Granada (50 males), with an average age of 46.91 years (SD = 8.15). They were recruited between 2009 and 2013 at an occupational health clinic providing smoking cessation treatment. Baseline measures included socio-demographic data, preferred brand of cigarettes, number of years smoking, use of alcohol and/or tranquilizers, past attempts to quit, Fargerström Test for Nicotine Dependence, Smoking Processes of Change Scale, and Coping with Withdrawal Symptoms Interview. Participants were invited to a face-to-face assessment of smoking abstinence using self-report and cooximetry hemoglobin measures at 3, 6, and 12 months follow-up. The main outcome was smoking status coded as “relapse” versus “abstinence” at each follow-up. Kaplan-Meier survival analysis was performed to estimate the probability of continued abstinence during 12 months and log-rank tests were used to analyze differences in continued abstinence as a function of socio-demographic, smoking-, and treatment-related variables. Cox regression was used to analyze the simultaneous effect of several risk factors on abstinence.Results: Using alcohol and/or tranquilizers was related to shorter abstinence. Physical exercise, the number of treatment sessions, performance of treatment tasks, and coping with withdrawal symptoms were related to prolonged abstinence. In particular, failure to perform the treatment tasks tripled the risk of relapse, while lack of coping doubled it.Conclusions: Our results show that physical exercise, performance of treatment-related tasks, and effective coping with withdrawal symptoms can prolong abstinence from smoking. Programs designed to help quit smoking can benefit from the inclusion of these factors.This research was supported by the Occupational Medicine Area (Prevention Service) of the University of Granada

    Impact of comorbid psychiatric disorders on the outcome of substance abusers: a six year prospective follow-up in two Norwegian counties

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    BACKGROUND: Most help-seeking substance abusers have comorbid psychiatric disorders. The importance of such disorders for the long-term course of substance abuse is, however, still unclear. The aim of this paper is to describe six-year outcomes regarding death and relapse among alcoholics and poly-substance abusers and to analyse the predictive value of lifetime psychiatric disorders on relapse. METHODS: A consecutive sample of substance-dependent patients who received treatment in two counties in Norway (n = 287) was followed up after approximately six years. Information on socio-demographics, Axis I (CIDI) and II disorders (MCMI-II) and mental distress (HSCL-25) was gathered at baseline. At follow-up, detailed information regarding socio-demographics, use of substances (AUDIT and DUDIT) and mental distress (HSCL-25) was recorded (response rate: 63%). RESULTS: At six-year follow-up, 11% had died, most often male alcoholics (18%). Among the surviving patients, 70% had drug or alcohol related problems the year prior to follow-up. These patients were, classified as "relapsers". There were no significant differences in the relapse rate between women and men and among poly-substance abusers and alcoholics. The relapsers had an earlier onset of a substance use disorder, and more frequently major depression and agoraphobia. Multivariate analysis indicated that both psychiatric disorders (major depression) and substance use factors (early onset of a substance use disorder) were independent predictors of relapse. CONCLUSION: For reducing the risk of long-term relapse, assessment and treatment of major depression (and agoraphobia) are important. In addition, we are in need of a comprehensive treatment and rehabilitation program that also focuses on the addictive behaviour
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