AFM and Raman study of graphene deposited on silicon surfaces nanostructured by ion beam irradiation.

Nanoscale structures were produced on silicon surfaces by low-energy oxygen ion irradiation: periodic rippled or terraced patterns formed spontaneously, depending on the chosen combination of beam incidence angle and ion fluence. Atomic force microscopy image processing and analysis accurately described the obtained nanotopographies. Graphene monolayers grown by chemical vapour deposition were transferred onto the nanostructured silicon surfaces. The interfacial interaction between the textured surface and the deposited graphene governs the conformation of the thin carbon layer; the resulting different degree of regularity and conformality of the substrate-induced graphene corrugations was studied and it was related to the distinctive topographical features of the silicon nanostructures. Raman spectroscopy revealed specific features of the strain caused by the alternating suspension and contact with the underlying nanostructures and the consequent modulation of the silicon-graphene interaction. Lay Description In the field of nanosciences, nanotechnologies and advanced materials, it is pivotal to produce and integrate nanostructures in a controlled, cost-effective and possibly high-throughput manner. Currently, the surface nanopatterning by ion beam irradiation (IBI) is showing its potential in overcoming some of the limits that characterize the conventional lithographic techniques. IBI can produce self-organized and regular patterns of nanostructures, such as ripples, dots, and holes, having heights and lateral periodicities in a pre-defined range. The nanopatterns can develop over large surface areas of a broad class of materials and have been tested for different applications, e.g. microelectronic device fabrication, catalysis, nanoscale magnetism, surface-enhanced Raman scattering. Also, the ion-induced patterns allowed the control of physical properties such as wettability, reflectance, and photoluminescence. As a whole, this is a highly dynamic and continuously evolving field. Graphene was first obtained from bulk graphite by mechanical exfoliation; remarkable mechanical, thermal and optical properties came to light; they make graphene an ideal material for sensing. Also, the research on graphene paves the way for basic and applied studies on other ultrathin thickness materials, such as monolayer transition metal dichalcogenide or monolayer metal oxide, which also show peculiar properties as compared to their bulk version. Since graphene is a zero-gap semi-metal, a finite energy gap must be open to engineer graphene-based electronic devices. At this aim, researchers can take advantage of the mechanical properties of graphene, since its out-of-plane deformation can favourably modify its electronic structure. While the spontaneous, random self-folding of graphene to form wrinkles has thermodynamics reasons and is unavoidable above a certain material length, the interactions between graphene and substrates can generate, in principle, designed wrinkled structures. Therefore, a field of study has emerged, focused on the control and tuning of the geometry of graphene corrugations and their influence on specific physical and chemical properties. To the best of our knowledge, this work studies for the first time the geometry and strain in graphene wrinkles induced by silicon substrates that were suitably nanopatterned by ion beam irradiation.

Pollen discrimination and classification by Fourier transform infrared (FT-IR) microspectroscopy and machine learning.

The discrimination and classification of allergy-relevant pollen was studied for the first time by mid-infrared Fourier transform infrared (FT-IR) microspectroscopy together with unsupervised and supervised multivariate statistical methods. Pollen samples of 11 different taxa were collected, whose outdoor air concentration during the flowering time is typically measured by aerobiological monitoring networks. Unsupervised hierarchical cluster analysis provided valuable information about the reproducibility of FT-IR spectra of the same taxon acquired either from one pollen grain in a 25 x 25 microm2 area or from a group of grains inside a 100 x 100 microm2 area. As regards the supervised learning method, best results were achieved using a K nearest neighbors classifier and the leave-one-out cross-validation procedure on the dataset composed of single pollen grain spectra (overall accuracy 84%). FT-IR microspectroscopy is therefore a reliable method for discrimination and classification of allergenic pollen. The limits of its practical application to the monitoring performed in the aerobiological stations were also discussed.

Management of cardiac device infections: A retrospective survey of a non-surgical approach combining antibiotic therapy with transvenous removal.

Pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) have become life-saving therapeutic tools for patients with cardiac arrhythmia. Complications include thrombosis, embolism and infections at a highly variable rate. Surgical removal of the infected device has been perceived as the only way to guarantee a successful outcome and to reduce the high risk of mortality. Recently, a transvenous extraction method has been developed to remove infected intracardiac leads without sternotomy. This survey was designed to evaluate the outcome of an approach combining antibiotic therapy with non-surgical transvenous complete removal for the management of cardiac device infections (CDIs). We reviewed case-histories of 121 patients (105 with PM and 16 with ICD infections). The aim of our retrospective survey was to ascertain that a non-invasive transvenous complete removal of the infected devices is safe and effective when associated with appropriate antibiotic therapy starting 10 days before the procedure and extending to at least three weeks after. The infected devices were successfully removed in all patients with a non-surgical transvenous technique. The infections were most frequently caused by coagulase-negative staphylococci (70%), Staphylococcus aureus (14%), and Gram-negative rods (12%). Polymicrobial infections were documented in 19 patients and represent 16% of all device-related infections. The removal of the devices was done during antibiotic therapy, administered for a median of 26 days (range 23 to 45 days). Neither fatalities nor relapse of infections were recorded in the patient population during the one-year follow-up visits. According to our experience, CDIs can be treated with antibiotic therapy and non-surgical removal of the entire infected device, thus allowing a successful reimplantation. This procedure prevents recurrent infections and operative mortality.

Impact of blunted pulmonary venous flow on the outcome of patients with left ventricular systolic dysfunction secondary to either ischemic or idiopathic dilated cardiomyopathy.

The intravenous administration of echo contrast agents enhances the Doppler signal and makes the study of pulmonary venous flow (PVF) easily achievable by transthoracic echocardiography. The aim of this study was to evaluate whether PVF patterns play a role in predicting the outcome of patients with left ventricular (LV) systolic dysfunction. Thus, 115 patients (79 men, mean age 69 years) with LV dysfunction (ejection fraction [EF] <45%) due to either ischemic or idiopathic dilated cardiomyopathy were studied and followed-up for 1 year. A quantitative interrogation of all components of PVF was feasible in 69% of patients at standard transthoracic examination; after contrast enhancement, anterograde and retrograde flow velocities were measurable in 100% and 92% of patients, respectively. A blunted PVF (defined by a systolic-to-diastolic peak velocity ratio <1) was identified in 48 patients (42%), who had a worse clinical status, a lower LVEF, and a more severe pulmonary hypertension. Thirty-six patients had cardiac events at follow-up: sudden death in 4, progressive heart failure in 12, and hospitalization for worsening heart failure in 20 patients. Multivariate Cox proportional-hazards analysis revealed that advanced New York Heart Association class, male gender, and older age were independent predictors of mortality. However, blunted PVF, reduced LVEF, older age, and increased heart rate in descending order of power were independent predictors of heart failure hospitalizations and deaths from end-stage heart failure. In conclusion, the assessments of PVF may effectively contribute to the characterization of patients with LV dysfunction and to the prediction of their outcome.

[Pulmonary hypertension in patients with left ventricular dysfunction studied with contrast-enhanced Doppler echocardiography: relations with diastolic parameters and prognostic implications]. / Studio dell'ipertensione polmonare in pazienti con disfunzione ventricolare sinistra mediante eco-Doppler con contrasto: rapporti con i parametri diastolici e implicazioni prognostiche.

In patients with left ventricular dysfunction, the prognostic value of both pulmonary hypertension and mitral flow patterns has been recognized. However, the effect of the association of different degrees of pulmonary hypertension on prognosis and the corresponding left ventricular diastolic dysfunction is not clear. Accordingly, we considered the impact on survival of a categorization based on the relationship between pulmonary artery pressure and left ventricular diastolic dysfunction, as assessed by mitral and pulmonary venous flow analyses. Transthoracic Doppler echocardiography was carried out in 92 patients with ejection fraction < 45%, pulmonary artery systolic pressure > 25 mmHg and sinus rhythm. Tricuspid regurgitant velocity and Doppler parameters derived from transmitral and pulmonary venous flows were evaluated. In the case of inadequate baseline tracings, weak or poor Doppler signals were enhanced by intravenous injection of a galactose-based contrast agent (Levovist 8 ml suspension at a concentration of 400 mg/ml). To select those whose pulmonary hypertension was either proportional or unproportional to left side filling pressures, patients were divided as follows: Group 1 (n = 69) with low discrepancies and Group 2 (n = 23) with marked discrepancies between Doppler estimates of pulmonary artery systolic pressure and left side filling abnormalities. The patients of each group were also classified according to their mitral flow pattern: abnormal relaxation, pseudonormal and restrictive. Mean pulmonary artery systolic pressure was 49 +/- 16 mmHg in the total population, 43 +/- 11 mmHg in Group 1 and 68 +/- 14 mmHg in Group 2 (p < 0.0001). Several mitral and pulmonary venous flow variables significantly correlated with pulmonary artery systolic pressure in the total population and in the study groups. The best correlations were observed in Group 1 as regards the ratio of reverse-to-forward atrial wave duration (r = 0.83), E wave deceleration rate (r = 0.81), E wave deceleration time (r = -0.81) and the systolic fraction of pulmonary venous flow peak velocities (r = -0.75). In Group 1, the lower heart failure-free survival rate at 10 months was observed in patients with restrictive pattern (68%) as opposed to those with pseudonormal (94%) and abnormal relaxation patterns (97%). The overall heart failure-free survival rate in Group 2 was 86%. In conclusion, the classification according to the relationship between pulmonary hypertension and the alterations of left chamber filling may contribute to the prognostic stratification of patients with left ventricular dysfunction. The patients with pulmonary hypertension proportional to the increase in left chamber filling pressures and restrictive pattern exhibited the worst prognosis.

Dose-finding study and pharmacokinetics of epirubicin and paclitaxel over 3 hours: a regimen with high activity and low cardiotoxicity in advanced breast cancer.

PURPOSE: To determine the maximum-tolerated dose (MTD) of paclitaxel over 3 hours with a fixed dose of epirubicin, to investigate the plasma pharmacokinetics of this combination, and to evaluate the toxicity and the activity in previously untreated metastatic breast cancer patients. PATIENTS AND METHODS: Fifty patients with metastatic breast cancer, measurable disease, and normal left ventricular ejection fraction (LVEF) were eligible. Epirubicin was administered as an intravenous (I.V.) bolus at the fixed dose of 90 mg/m2 before the infusion of paclitaxel over 3 hours. The initial dose of paclitaxel was 135 mg/m2 and was increased by 20 mg/m2 in subsequent cohorts of six patients until dose-limiting toxicity (DLT). Plasma pharmacokinetics of paclitaxel and epirubicin was performed at cycle 1 in at least two patients per dose level of paclitaxel (175 up to 225 mg/m2). RESULTS: The DLT of this combination was febrile neutropenia in two of eight patients who received paclitaxel at 225 mg/m2. The mean peak plasma concentration of paclitaxel ranged between 5.1 and 6.2 micromol/L at doses of 175 to 225 mg/m2. The concentration of epirubicinol decreased from 47.3 +/- 9.4 to 37.9 +/- 7.5 ng/mL in patients treated with paclitaxel 175 and 225 mg/m2. The most relevant toxicity was grade 4 neutropenia (61% of all courses). The pharmacokinetic data of paclitaxel, in particular the time above the threshold level of 0.05 micromol/L, were not significantly related to myelosuppression. Cardiac toxicity was mild: three patients (6%) developed mild congestive heart failure that was responsive to therapy. Among 49 assessable patients, 41 responses (84%; 95% confidence interval [CI], 70% to 92%) were observed, and nine (18%) of these were complete. CONCLUSION: Our study demonstrates that (1) the MTD is epirubicin 90 mg/m2 and paclitaxel 200 mg/m2; (2) no clear relationship exists between pharmacokinetic data of paclitaxel and myelosuppression, while the increase in the dose of paclitaxel is associated with a reduction in epirubicinol plasma levels; and (3) the association is feasible, with low cardiotoxicity, and has a high activity in metastatic breast cancer.

[An echographic study of left ventricular function in acute myocardial infarct undergoing thrombolysis]. / Studio ecocardiografico della funzione ventricolare sinistra nell'infarto miocardico acuto sottoposto a trombolisi.

To evaluate the changes of left ventricular diastolic and systolic function and the timing of these changes in the early stages of acute myocardial infarction, serial echocardiograms were performed in 10 male patients (mean age of 56 years) with acute myocardial infarction, undergoing reperfusion by thrombolysis (recombinant tissue plasminogen activator). Echocardiograms were performed before reperfusion and 3, 6, 12, 24, 48, 72 hours, 7 and 14 days after thrombolysis. Significant differences of heart rate, systolic and diastolic blood pressure, left ventricular end diastolic volume, end-systolic volume and ejection fraction were not found. The mean regional wall motion index improved from 1.02 +/- 0.50 to 0.89 +/- 0.51 (p less than 0.05) at 48 hours; to 0.79 +/- 0.46 (p less than 0.01) at 72 hours; to 0.69 +/- 0.43 (p less than 0.001) at 7 days and to 0.61 +/- 0.40 at 14 days (p less than 0.001). The deceleration time decreased from 223 +/- 33 to 169 +/- 30 ms (p less than 0.001) 24 hours after reperfusion without further improvement. E peak velocity and E/A ratio significantly increased at 72 hours, while A peak velocity was not statistically different. A slow and progressive recovery of left ventricular function occurred after thrombolysis in acute myocardial infarction. Left ventricular diastole improves earlier while regional systolic function improves slowly till the hospital discharge.