Electrical, mechanical and electromechanical properties of graphene-thermoset polymer composites produced using acetone-DMF solvents

Recently, graphene-polymer composites gained a central role in advanced stress and strain sensing. A fundamental step in the production of epoxy-composites filled with graphene nanoplatelets (GNPs) consists in the exfoliation and dispersion of expanded graphite in a proper solvent, in the mixing of the resulting GNP suspension with the polymer matrix, and in the final removal of the solvent from the composite before curing through evaporation. The effects of traces of residual solvent on polymer curing process are usually overlooked, even if it has been found that even a small amount of residual solvent can affect the mechanical properties of the final composite. In this paper, we show that residual traces of N,N′-Dimethylformamide (DMF) in vinylester epoxy composites can induce relevant variations of the electrical, mechanical and electromechanical properties of the cured GNP-composite. To this purpose, a complete analysis of the morphological and structural characteristics of the composite samples produced using different solvent mixtures (combining acetone and DMF) is performed. Moreover, electrical, mechanical and electromechanical properties of the produced composites are assessed. In particular, the effect on the piezoresistive response of the use of DMF in the solvent mixture is analyzed using an experimental strain dependent percolation law to fit the measured electromechanical data. It is shown that the composites realized using a higher amount of DMF are characterized by a higher electrical conductivity and by a strong reduction of Young’s Modulus

Electromagnetic and electromechanical applications of graphene-based materials

This volume contains the extended abstracts of the contributions presented at the workshop Nanoscale Excitations in Emergent Materials (NEEM 2015) held in Rome from 12 to 14 October 2015, an event organized and supported in the framework of the Bilateral Cooperation Agreement between Italy and India within the project of major relevance "Investigating local structure and magnetism of cobalt nano-structures", funded by the Italian Ministry of Foreign Affairs and the Department of Science and Technology in India

In vitro transcription profiling of the σS subunit of bacterial RNA polymerase: re-definition of the σS regulon and identification of σS-specific promoter sequence elements

Specific promoter recognition by bacterial RNA polymerase is mediated by σ subunits, which assemble with RNA polymerase core enzyme (E) during transcription initiation. However, σ70 (the housekeeping σ subunit) and σS (an alternative σ subunit mostly active during slow growth) recognize almost identical promoter sequences, thus raising the question of how promoter selectivity is achieved in the bacterial cell. To identify novel sequence determinants for selective promoter recognition, we performed run-off/microarray (ROMA) experiments with RNA polymerase saturated either with σ70 (Eσ70) or with σS (EσS) using the whole Escherichia coli genome as DNA template. We found that Eσ70, in the absence of any additional transcription factor, preferentially transcribes genes associated with fast growth (e.g. ribosomal operons). In contrast, EσS efficiently transcribes genes involved in stress responses, secondary metabolism as well as RNAs from intergenic regions with yet-unknown function. Promoter sequence comparison suggests that, in addition to different conservation of the −35 sequence and of the UP element, selective promoter recognition by either form of RNA polymerase can be affected by the A/T content in the −10/+1 region. Indeed, site-directed mutagenesis experiments confirmed that an A/T bias in the −10/+1 region could improve promoter recognition by Eσ

Anti-Ro52 antibodies positivity in antisynthetase syndrome: a single centre cohort study

Objectives: Although antisynthetase antibodies (ARS) are the established markers of the so-called antisynthetase syndrome (ASSD), in these patients the concomitant positivity of anti-Ro52 antibodies, reported in up to the 50% of cases, is not rare. Several studies focused on the effect of different ARS specificities on the evolution of ASSD, the most recent showing no effects. On the contrary, the role of co-occurring anti-Ro52 antibodies in ASSD is still debated. We investigated the potential of anti-Ro52 antibodies in identifying a clinical phenotype of ASSD or influencing prognosis, irrespectively to the underlying ARS specificity. Methods: Retrospective analysis of clinical, imaging and laboratory characteristics, therapeutic approaches and outcome at baseline and at last follow-up, of 60 ASSD patients progressively enrolled at our Hospital. Results: We identified 34 anti-Ro+ and 26 anti-Ro- ASSD patients. Classic triad prevalence at baseline was similar between the two groups, whereas interstitial lung disease (ILD) (p value=0.01) and myositis (p value=0.03) were significantly more prevalent in anti-Ro52+ and in anti-Ro52- patients at last follow up, respectively. No differences in therapeutic approaches, oxygen need and ILD patterns were observed. Overall mortality was 25% (15 subjects). No differences in mortality, overall and disease related, between anti-Ro52+ and anti-Ro52- patients were observed (p value=0.764), despite the more frequent ILD occurrence in anti-Ro52+ patients. Survival curves were not different at any time point (Log-rank test, p value 0.98). Conclusions: Anti-Ro52 antibodies affect time course and clinical characteristics of ASSD. Although ILD is significantly more associated to anti-Ro52 antibodies, no difference in mortality was observed compared to anti-Ro52 negative patients

Effects of combined strength and endurance training on exercise capacity in kidney transplant cyclists and runners

Introduction: After transplantation, engaging in regular physical activity (PA) or sport is recommended for health. Participation to competitive sports is increasingly common among kidney transplant recipients while little is known on how training affects the physical performance in transplanted athletes. Aim: The purpose of this case study was to assess the effects of a tailored training program on exercise parameters in kidney transplant cyclists (CKTRs) and runners (RKTRs). Methods: Twelve male transplanted athletes were enrolled. The workload at aerobic and anaerobic thresholds, the submaximal aerobic power (V'O2 stage) and rate of perceived exertion (RPE) during an incremental cycling or running test, and the peak instantaneous force (PIF) during a countermovement jump were assessed at baseline (T0) and after 6 months of tailored training (T6) consisting in strength and aerobic exercises. Exercise adherence, blood lipid profile and renal function were also investigated. Results: Eight CKTRs and 4 RKTRs completed the 6-month training period, with a significant increase of training volume (minutes/week). The exercise adherence was met by 90% in both groups. At T6, there were significant (p<0.05) improvements of maximum workload attained, the workload corresponding to the aerobic threshold and PIF, while workloads at anaerobic threshold, V'O2 stage and RPE were unchanged. Blood cholesterol significantly decreased (p<0.01), while the other blood parameters were unchanged. Conclusions: These findings indicate that the combined strength and endurance training is well tolerated and may improve exercise performance in this selected population of KTRs

Transmission through graphene of electrons in the 30 – 900 eV range

Here, we report on accurate transmission measurements of electrons below 1 keV through suspended monolayer graphene. Monolayer graphene was grown via chemical vapor deposition and transferred onto transmission electron microscopy (TEM) grids. A monochromatic electron gun has been employed to perform the measurements in the 30 – 900 eV range in ultra-high vacuum. The graphene transparency is obtained from the absolute measurement of the direct beam current and the transmitted one, by means of a Faraday cup. We observed a transmission going from 20 to 80% for monolayer graphene within the experimental electron energy range. The high quality and the grid coverage of the suspended graphene has been proved via micro-Raman, X-ray photoemission, electron energy loss spectroscopies and field-emission scanning electron microscopy. After a 550 °C in-vacuum annealing of the samples, the main contribution to the C 1s spectrum is due to the component and the evidence of suspended monolayer graphene has been observed through the -plasmon excitation

Role of inflammatory and immune-nutritional prognostic markers in patients undergoing surgical resection for biliary tract cancers

The relationship between immune-nutritional status and tumor growth; biological aggressiveness and survival, is still debated. Therefore, this study aimed to evaluate the prognostic performance of different inflammatory and immune-nutritional markers in patients who underwent surgery for biliary tract cancer (BTC). The prognostic role of the following inflammatory and immune-nutritional markers were investigated: Glasgow Prognostic Score (GPS), modified Glasgow Prognostic Score (mGPS), Prognostic Index (PI), Neutrophil to Lymphocyte ratio (NLR), Platelet to Lymphocyte ratio (PLR), Lymphocyte to Monocyte ratio (LMR), Prognostic Nutritional Index (PNI). A total of 282 patients undergoing surgery for BTC were included. According to Cox regression and ROC curves analysis for survival, LMR had the best prognostic performances, with hazard ratio (HR) of 1.656 (p = 0.005) and AUC of 0.652. Multivariable survival analysis identified the following independent prognostic factors: type of BTC (p = 0.002), T stage (p = 0.014), N stage (p < 0.001), histological grading (p = 0.045), and LMR (p = 0.025). Conversely, PNI was related to higher risk of severe morbidity (p < 0.001) and postoperative mortality (p = 0.005). In conclusion, LMR appears an independent prognostic factor of long-term survival, whilst PNI seems associated with worse short-term outcomes

MicroRNA expression in HTLV-1 infection and pathogenesis

Our laboratory is examining the profiles of microRNA expression in ATLL cells and infected T-cell lines using microarrays and small RNA libraries. Microarray analysis of ATLL samples revealed 6 upregulated and 21 downregulated microRNAs in ATLL cells compared to CD4+ T-cell controls. Potential targets for deregulated microRNAs were identified by integrating microRNA and mRNA expression profiles. Current experiments are aimed at verifying these predicted microRNA-target interactions

Single center experience with laparoscopic adrenalectomy on a large clinical series

BACKGROUND: Laparoscopic adrenalectomy is considered the gold standard technique for the treatment of benign small and medium size adrenal masses (<6 cm), due to low morbidity rate, short hospitalization and patient rapid recovery. The aim of our study is to analyse the feasibility and efficiency of this surgical approach in a broad spectrum of adrenal gland pathologies. METHODS: Pre-operative, intra-operative and post-operative data from 126 patients undergone laparoscopic adrenalectomy between January 2003 and December 2015 were retrospectively collected and reviewed. Diagnosis was obtained on the basis of clinical examination, laboratory values and imaging techniques. Doxazosin was preoperatively administered in case of pheochromocytoma while spironolactone and potassium were employed to treat Conn's disease. Laparoscopic adrenalectomies were all performed by the same surgeon (CG). First 30 procedures were considered as learning curve adrenalectomies. RESULTS: One hundred twenty-six patients were included in the study. Functioning tumors were diagnosed in 84 patients, 27 patients were affected by pheochromocytomas, 29 by Conn's disease, 28 by Cushing disease. Surgery mean operative time was 137.33 min (range 100-180) during the learning curve adrenalectomies and 96.5 min (range 75-110) in subsequent procedures. Mean blood loss was respectively 160.2 ml (range 60-280) and 90.5 ml (range 50-200) in the first 30 procedures and the subsequent ones. Only one conversion to open surgery occurred. No post-operative major complications were observed, while minor complications occurred in 8 patients (0,79%). In 83 out of 84 functioning neoplasms, laparoscopic adrenalectomy was effective in normalization of endocrine profile. CONCLUSIONS: Laparoscopic adrenalectomy is a safe and feasible procedure, even for functioning masses and pheochromocytomas. A multidisciplinary team including endocrinologists, endocrine surgeons and anaesthesiologists, is recommended in the management of adrenal pathology, and adrenal surgery should be performed in referral high volume centers. A thirty-procedures learning curve is recommended to improve surgical outcomes