Surface doping in T6/ PDI-8CN2 Heterostructures investigated by transport and photoemission measurements

In this paper, we discuss the surface doping in sexithiophene (T6) organic field-effect transistors by PDI-8CN2. We show that an accumulation heterojunction is formed at the interface between the organic semiconductors and that the consequent band bending in T6 caused by PDI-8CN2 deposition can be addressed as the cause of the surface doping in T6 transistors. Several evidences of this phenomenon have been furnished both by electrical transport and photoemission measurements, namely the increase in the conductivity, the shift of the threshold voltage and the shift of the T6 HOMO peak towards higher binding energies.Comment: 5 pages, 5 figure

Interfacing aptamers, nanoparticles and graphene in a hierarchical structure for highly selective detection of biomolecules in OECT devices

In several biomedical applications, the detection of biomarkers demands high sensitivity, selectivity and easy-to-use devices. Organic electrochemical transistors (OECTs) represent a promising class of devices combining a minimal invasiveness and good signal transduction. However, OECTs lack of intrinsic selectivity that should be implemented by specific approaches to make them well suitable for biomedical applications. Here, we report on a biosensor in which selectivity and a high sensitivity are achieved by interfacing, in an OECT architecture, a novel gate electrode based on aptamers, Au nanoparticles and graphene hierarchically organized to optimize the final response. The fabricated biosensor performs state of the art limit of detection monitoring biomolecules, such as thrombin-with a limit of detection in the picomolar range (≤ 5 pM) and a very good selectivity even in presence of supraphysiological concentrations of Bovine Serum Albumin (BSA-1mM). These accomplishments are the final result of the gate hierarchic structure that reduces sterich indrance that could contrast the recognition events and minimizes false positive, because of the low affinity of graphene towards the physiological environment. Since our approach can be easily applied to a large variety of different biomarkers, we envisage a relevant potential for a large series of different biomedical applications

Synthesis of single layer graphene on Cu(111) by C-60 supersonic molecular beam epitaxy

We acknowledge funding from the EU under the FP7th grant agreement 604391 (Graphene Flagship), from FBK via the CMM Director grant “SuperCar”, and PRIN project DESCARTES (no. 2010BNZ3F2), MIUR, Italy. N. M. P. is supported by ERC StG Ideas 2011 BIHSNAM (no. 279985), ERC PoC 2013-1 REPLICA2 (no. 619448), and by ERC PoC 2013-2 KNOTOUGH (no. 632277). S. T., N. M. P. and G. G. are also supported by the Provincia Autonoma di Trento (“Graphene nanocomposites”, no. S116/2012-242637 and reg. delib. no. 2266). G. G. and S. T. acknowledge support by INFN through the “Supercalcolo” agreement with FBK. S. T. gratefully acknowledges the Institute for Advanced Studies in Bologna for supporting his ISA fellowship

Detection of Nitroaromatic Explosives in Air by Amino-Functionalized Carbon Nanotubes

Nitroaromatic explosives are the most common explosives, and their detection is important to public security, human health, and environmental protection. In particular, the detection of solid explosives through directly revealing the presence of their vapors in air would be desirable for compact and portable devices. In this study, amino-functionalized carbon nanotubes were used to produce resistive sensors to detect nitroaromatic explosives by interaction with their vapors. Devices formed by carbon nanotube networks working at room temperature revealed trinitrotoluene, one of the most common nitroaromatic explosives, and di-nitrotoluene-saturated vapors, with reaction and recovery times of a few and tens of seconds, respectively. This type of resistive device is particularly simple and may be easily combined with low-power electronics for preparing portable devices

A novel combined experimental and multiscale theoretical approach to unravel the structure of SiC/SiOx core/shell nanowires for their optimal design

In this work we propose a realistic model of nanometer-thick SiC/SiOxcore/shell nanowires (NWs) using a combined first-principles and experimental approach. SiC/SiOxcore/shell NWs were first synthesised by a low-cost carbothermal method and their chemical-physical experimental analysis was accomplished by recording X-ray absorption near-edge spectra. In particular, the K-edge absorption lineshapes of C, O, and Si are used to validate our computational model of the SiC/SiOxcore/shell NW architectures, obtained by a multiscale approach, including molecular dynamics, tight-binding and density functional simulations. Moreover, we present ab initio calculations of the electronic structure of hydrogenated SiC and SiC/SiOxcore/shell NWs, studying the modification induced by several different substitutional defects and impurities into both the surface and the interfacial region between the SiC core and the SiOxshell. We find that on the one hand the electron quantum confinement results in a broadening of the band gap, while hydroxyl surface terminations decrease it. This computational investigation shows that our model of SiC/SiOxcore/shell NWs is capable to deliver an accurate interpretation of the recorded X-ray absorption near-edge spectra and proves to be a valuable tool towards the optimal design and application of these nanosystems in actual devices

Prognostic Role of Bacterial and Fungal Infections in Patients with Liver Cirrhosis with and without Acute-on-Chronic Liver Failure: A Prospective 2-Center Study

Background. Bacterial and fungal infections (BFIs) are frequent in patients with cirrhosis and often trigger acute-on-chronic liver failure (ACLF). This prospective observational study aims to describe the interactions between BFI and ACLF in terms of mortality and related risk factors. Methods. We performed a 2-center prospective observational study enrolling hospitalized patients with cirrhosis admitted for acute decompensation. Data were recorded at admission and during hospitalization. Survival was recorded up to 1 year. Results. Among the 516 patients enrolled, 108 (21%) were infected at admission, while an additional 61 patients (12%) developed an infection during hospital stay. In the absence of ACLF, the 1-year mortality rate of patients with BFI did not differ from that of patients without BFI (33% vs 31%; P = .553). In contrast, those with ACLF triggered or complicated by BFI had a significantly higher mortality rate than those who remained free from BFI (75% vs 54%; P = .011). Competing risk analysis showed that the negative impact of ACLF-related BFI on long-term prognosis was independent from Model for End-stage Liver Disease (MELD) incorporating serum sodium concentration score, comorbidity, and basal C-reactive protein level. Finally, multivariable logistic regression showed that higher MELD score (P < .001), QuickSOFA score ≥2 points (P = .007), and secondary bloodstream (P = .022) and multidrug-resistant pathogen isolation (P = .030) were independently associated with ACLF in patients with BFI. Conclusions. This large prospective study indicated that the adverse impact of BFI on long-term survival in decompensated cirrhosis is not universal but is limited to those patients who also develop ACLF. Both disease severity and microbiological factors predispose infected decompensated patients to ACLF

Impact of social determinants on antiretroviral therapy access and outcomes entering the era of universal treatment for people living with HIV in Italy

Background: Social determinants are known to be a driving force of health inequalities, even in high income countries. Aim of our study was to determine if these factors can limit antiretroviral therapy (ART) access, outcome and retention in care of people living with HIV (PLHIV) in Italy. Methods: All ART naïve HIV+ patients (pts) of Italian nationality enrolled in the ICONA Cohort from 2002 to 2016 were included. The association of socio-demographic characteristics (age, sex, risk factor for HIV infection, educational level, occupational status and residency area) with time to: ART initiation (from the first positive anti-HIV test), ART regimen discontinuation, and first HIV-RNA < 50 cp/mL, were evaluated by Cox regression analysis, Kaplan Meier method and log-rank test. Results: A total of 8023 HIV+ pts (82% males, median age at first pos anti-HIV test 36 years, IQR: 29-44) were included: 6214 (77.5%) started ART during the study period. Women, people who inject drugs (PWID) and residents in Southern Italy presented the lowest levels of education and the highest rate of unemployment compared to other groups. Females, pts aged > 50 yrs., unemployed vs employed, and people with lower educational levels presented the lowest CD4 count at ART initiation compared to other groups. The overall median time to ART initiation was 0.6 years (yrs) (IQR 0.1-3.7), with a significant decrease over time [2002-2006 = 3.3 yrs. (0.2-9.4); 2007-2011 = 1.0 yrs. (0.1-3.9); 2012-2016 = 0.2 yrs. (0.1-2.1), p < 0.001]. By multivariate analysis, females (p < 0.01) and PWID (p < 0.001), presented a longer time to ART initiation, while older people (p < 0.001), people with higher educational levels (p < 0.001), unemployed (p = 0.02) and students (p < 0.001) were more likely to initiate ART. Moreover, PWID, unemployed vs stable employed, and pts. with lower educational levels showed a lower 1-year probability of achieving HIV-RNA suppression, while females, older patients, men who have sex with men (MSM), unemployed had higher 1-year risk of first-line ART discontinuation. Conclusions: Despite median time to ART start decreased from 2002 to 2016, socio-demographic factors still contribute to disparities in ART initiation, outcome and durability

Impact of safety-related dose reductions or discontinuations on sustained virologic response in HCV-infected patients: Results from the GUARD-C Cohort

BACKGROUND: Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice. METHODS: A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively. RESULTS: SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced 651 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with 651 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not 655. CONCLUSIONS: In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginterferon alfa-2a/ribavirin

Prognostic Value of the Fibrosis-4 Index in Human Immunodeficiency Virus Type-1 Infected Patients Initiating Antiretroviral Therapy with or without Hepatitis C Virus

Objective: To evaluate the Fibrosis (FIB)-4 index as a predictor of major liver-related events (LRE) and liver-related death (LRD) in human immunodeficiency virus (HIV) type-1 patients initiating combination antiretroviral therapy (cART). Design: Retrospective analysis of a prospective cohort study. Setting: Italian HIV care centers participating to the ICONA Foundation cohort. Participants: Treatment-naive patients enrolled in ICONA were selected who: initiated cART, had hepatitis C virus (HCV) serology results, were HBsAg negative, had an available FIB-4 index at cART start and during follow up. Methods: Cox regression models were used to determine the association of FIB4 with the risk of major LRE (gastrointestinal bleeding, ascites, hepatic encephalopathy, hepato-renal syndrome or hepatocellular carcinoma) or LRD. Results: Three-thousand four-hundred seventy-five patients were enrolled: 73.3% were males, 27.2% HCV seropositive. At baseline (time of cART initiation) their median age was 39 years, had a median CD4+ T cell count of 260 cells/uL, and median HIV RNA 4.9 log copies/ mL, 65.9% had a FIB-4 &lt; 1.45, 26.4% 1.45-3.25 and 7.7% &gt; 3.25. Over a follow up of 18,662 person-years, 41 events were observed: 25 major LRE and 16 LRD (incidence rate, IR, 2.2 per 1,000 PYFU [95% confidence interval, CI 1.6-3.0]). IR was higher in HCV seropositives as compared to negatives (5.9 vs 0.5 per 1,000 PYFU). Higher baseline FIB-4 category as compared to &lt; 1.45 (FIB-4 1.45-3.25: HR 3.55, 95% CI 1.09-11.58; FIB-4 &gt; 3.25: HR 4.25, 1.21-14.92) and time-updated FIB-4 (FIB-4 1.45-3.25: HR 3.40, 1.02-11.40; FIB- 4&gt; 3.25: HR 21.24, 6.75-66.84) were independently predictive of major LRE/LRD, after adjusting for HIV- and HCV-related variables, alcohol consumption and type of cART. Conclusions: The FIB-4 index at cART initiation, and its modification over time are risk factors for major LRE or LRD, independently of infection with HCV and could be used to monitor patients on cART

Incidence and factors associated with the risk of sexually transmitted diseases in HIV-infected people seen for care in Italy: data from the Icona Foundation cohort.

Objectives: The aims of this study were to identify temporal trends in the incidence of sexually transmitted diseases (STDs) in a cohort of HIV-infected people and to evaluate factors associated with the risk of a new STD diagnosis. Methods: All HIV-infected patients in the Icona Foundation Study cohort enrolled after 1998 were included in this study. STD incidence rates (IRs) were calculated and stratified by calendar period. Predictors of STDs were identified using a Poisson regression model with sandwich estimates for standard errors. Results: Data for 9168 participants were analysed [median age 37.3 (range 18-81) years; 74% male; 30% men who have sex with men (MSM)]. Over 46 736 person-years of follow-up (PYFU), 996 episodes of STDs were observed [crude IR 21.3/1000 PYFU; 95% confidence interval (CI) 20.0-22.6/1000 PYFU]. In multivariable Poisson regression analysis, MSM [rate ratio (RR) 3.03; 95% CI 2.52-3.64 versus heterosexuals], calendar period (RR 1.67; 95% CI 1.42-1.97 for 2008-2012 versus 1998-2002), HIV RNA &gt; 50 HIV-1 RNA copies/mL (RR 1.44; 95% CI 1.19-1.74 versus HIV RNA ≤ 50 copies/mL) and a current CD4 count &lt; 100 cells/μL (RR 4.66; 95% CI 3.69-5.89; P &lt; 0.001 versus CD4 count &gt; 500 cells/μL) were associated with an increased risk of STDs. In contrast, older age (RR 0.82 per 10 years older; 95% CI 0.77-0.89) and being currently on ART (RR 0.38; 95% CI 0.33-0.45) compared with being ART-naïve or on a treatment interruption were associated with a lower risk of developing STDs. Conclusions: An increase in the incidence of STDs was observed in more recent years. Interventions to prevent STDs and potential spread of HIV should target the younger population, MSM and people currently not receiving ART