Transfer of CVD-grown graphene for room temperature gas sensors.

An easy transfer procedure to obtain graphene-based gas sensing devices operating at room temperature (RT) is presented. Starting from chemical vapor deposition-grown graphene on copper foil, we obtained single layer graphene which could be transferred onto arbitrary substrates. In particular, we placed single layer graphene on top of a SiO2/Si substrate with pre-patterned Pt electrodes to realize a chemiresistor gas sensor able to operate at RT. The responses to ammonia (10, 20, 30 ppm) and nitrogen dioxide (1, 2, 3 ppm) are shown at different values of relative humidity, in dark and under 254 nm UV light. In order to check the sensor selectivity, gas response has also been tested towards hydrogen, ethanol, acetone and carbon oxide. Finally, a model based on linear dispersion relation characteristic of graphene, which take into account humidity and UV light effects, has been proposed.

Diffusion-weighted whole-body MRI for evaluation of early response in multiple myeloma.

AIM: To evaluate the modifications of the apparent diffusion coefficient (ADC) in myelomatous lesions before and after induction treatment and the correlation with patient response to therapy according to International Myeloma Working Group (IMWG) criteria. MATERIALS AND METHODS: A homogeneous group of 18 patients with a diagnosis of symptomatic multiple myeloma who underwent whole-body MRI with diffusion-weighted imaging (DWI-MRI) before and after bortezomib-based induction chemotherapy were evaluated prospectively. Quantitative analysis of ADC maps of myelomatous lesions was performed with the following pattern types: focal pattern, diffuse pattern (moderate and severe), and "salt and pepper" pattern. Lesions were evaluated by quantitative image analysis including measurement of the mean ADC in three measurements. Imaging results were compared to laboratory results as the clinical reference standard. RESULTS: A statistically significant increase in ADC values were found in the lesions of patients that responded to treatment. Interestingly, focal lesions showed a strongly significant increase in ADC values in responders, whereas no significant variation in ADC value in non-focal lesions (diffuse pattern and "salt and peppers" pattern) between responders and non-responders group was demonstrated. CONCLUSIONS: DWI-MRI could provide additional quantitative information useful in monitoring early therapy response according to ADC changes of focal lesions.

Few layered MoS2 lithography with an AFM tip: description of the technique and nanospectroscopy investigations.

A novel technique to lithograph the MoS2 surface is described here. Mechanically exfoliated MoS2 flakes have been patterned with an atomic force microscope tip. After the patterning process, the lithographed areas have been removed by selective chemical etching. The electronic properties of the MoS2 flakes have been analyzed with spatially resolved photoelectron spectroscopy, with tunable incident photon energy, provided by a synchrotron light source. Tens of meV core level shifts can be recorded in relation to the flakes edges, coming from both the exfoliation and from the lithography.

Factors affecting long-term outcomes after thromboembolectomy for acute lower limb ischemia.

AIM: The aim of this study was to analyze factors influencing outcomes of surgical management for lower limb acute ischemia. METHODS: A retrospective analysis of 490 thromboembolectomies performed in 468 patients was conducted. Perioperative and follow-up results were analyzed. Univariate and multivariate analysis of clinical variables and patients' characteristics for the risk of reocclusion, amputation and mortality at 2 years were performed. Statistical significance was defined as a P value <0.05. RESULTS: Cumulative reocclusion, amputation and mortality rates at 24 months were 22.6%, 14.3% and 42.8%, respectively. At univariate analysis, the factors associated with increased 2-year reocclusion rate were severity of clinical presentation, current smoking habit, arterial thrombosis rather than embolism, atrial fibrillation and the avoidance of completion angiography. All these factors except clinical presentation maintained significance at multivariate analysis. Factors associated with increased 2-year amputation rate at univariate analysis included severity of clinical presentation, smoke, arterial thrombosis, atrial fibrillation and valvulopathy. All these factors except clinical presentation and valvular defects maintained significance at multivariate analysis. Factors associated with increased 2-year mortality rate at univariate analysis included age >80 years, arterial thrombosis, history of peripheral arterial disease and antiplatelet drugs. The same factors, except antiplatelet treatment, were found to be significant at multivariate analysis. CONCLUSION: Surgical intervention for lower limb ischemia is associated with high 2-year mortality but offers good 2-year limb salvage. The pattern of risk factors for reocclusion and amputation rates is quite different from those affecting mortality. Only thrombotic aetiology is a significant risk factor for all the three outcomes.

Lower extremity traumatic vascular injury at a level II trauma center: an analysis of limb loss risk factors and outcomes.

AIM: The objectives were to review in our series the risk factors, management and outcomes of patients who sustained vascular injuries in the lower limbs and to determine the effect of risk factors and treatment on the outcome of the injured extremity. METHODS: Fifty-six patients submitted to surgical treatment were retrospectively reviewed. Results were analysed in terms of type of operation and reconstruction, intraoperative and 30 day complications, reconstruction occlusion, major amputation and mortality. RESULTS: The mechanism of trauma was blunt in 30.4% and penetrating in 69.6%. The overall primary amputation rate was 5.4%, the overall secondary amputation rate was 1.8%. The overall intraoperative and postoperative mortality were 1.8% and 5.4% respectively. At univariate analysis, the presence of compartment syndrome and ischemia time >6 hours were associated with a significantly higher risk of early reconstruction thrombosis (both P=0.03). It showed also that the number of patent vessels (P=0.0000) and the presence of a MESS score >7 (P=0.0000) significantly affected primary amputation, and that the occurrence of postoperative deep wound infection or sepsis (P=0.0000), of tibio-peroneal trunk injury (P=0.003) and of a MESS score >7 (P=0.004) significantly affected secondary amputation. CONCLUSION: The number of patent arteries (0-1), the presence of a MESS score >7, the incidence of tibio-peroneal trunk injury and the occurrence of postoperative deep wound infection are significant independent factors for limb loss. The presence of compartment syndrome and of ischemia time >6 hours are associated with a significantly higher risk of early reconstruction thrombosis.

Role of nitric oxide in sleep regulation: effects of L-NAME, an inhibitor of nitric oxide synthase, on sleep in rats.

The effect of N(G)-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of enzyme nitric oxide synthase (NOS), on spontaneous sleep during the light period, was studied in adult rats implanted for chronic sleep recordings. L-NAME was injected by subcutaneous (s.c.) or intracerebroventricular (i.c.v.) routes or was infused directly into the dorsal raphe nuclei (DRN). Subcutaneous (1.25-5.0 mg/kg) or i.c.v. (0.25-1.0 mg) administration of L-NAME increased waking (W) and reduced slow wave sleep (SWS) and rapid-eye-movement sleep (REMS) during the first 3 h of recording. On the other hand, direct application of L-NAME into the DRN (50.0-150.0 microg) induced an increment of W and a reduction of SWS without suppressing REMS. Values of W and SWS were significantly different compared with those of controls during the 6-h recording period. The effects of L-NAME observed after s.c. or i.c.v. administration confirm previous studies in rabbits and rats, in which the NOS inhibitor reduced sleep and increased W in a dose-dependent manner. It is possible that REMS suppression after L-NAME could be related to a reduction of acetylcholine release in areas critical for REMS promotion. A decrease in gamma-aminobutyric acid (GABA) release after nitric oxide synthesis inhibition could play a role in the reduction of SWS.

Effects of accumbens m-chlorophenylbiguanide microinjections on sleep and waking in intact and 6-hydroxydopamine-treated rats.

Effects of the 5-HT3 receptor agonist, m-chlorophenylbiguanide (10.0-40.0 microg), on sleep and waking were studied in control, vehicle-treated and 6-hydroxydopamine-injected rats. Bilateral injections of m-chlorophenylbiguanide into the nucleus accumbens of the control and the vehicle-infused animals significantly increased waking and reduced slow wave sleep. Rapid eye movement sleep (REM sleep) remained unchanged. Pretreatment with the selective 5-HT3 receptor antagonist, MDL 72222 (1aH,3a,5a, H-tropan-3-yl-3,5-dichloro-benzoate) (0.5 mg/kg, s.c.), reversed the effects of m-chlorophenylbiguanide (10.0-20.0 microg) on sleep and waking in the control group. Administration of the 5-HT3 receptor agonist to the 6-hydroxydopamine-treated animals modified only slightly the time spent in wakefulness and slow wave sleep, while REM sleep was significantly and dose dependently reduced. Our findings further support the proposal that increase of wakefulness and reduction of slow wave sleep after activation of 5-HT3 receptors, is partly related to the release of endogenous dopamine.

Bovine herpesvirus 1 (BHV1) seroprevalence in the breeding cattle population of the Veneto region: prospects for the implementation of a control programme.

The results of a serological survey for bovine herpes virus (BHV1) antibodies in the breeding cattle population of the Veneto region are presented. The data do not support the hypothesis of an high prevalence of BHV1; on farms where vaccination was not carried out most animals were seronegative, and seropositive animals were generally older. Therefore, when drawing up the guidelines for a control programme, systematic immunization (with glycoprotein E-deleted vaccines) should be restricted only to farms with a high prevalence of BHV1 antibodies and/or with a high risk of BHV1 occurrence; in most unvaccinated farms a 'test and removal' policy appears to be more appropriate in order to rapidly eradicate BHV1 from the entire stock.

Effects of the D3 preferring dopamine agonist pramipexole on sleep and waking, locomotor activity and striatal dopamine release in rats.

Quantitation of 2 h sessions after administration of the D3 preferring dopamine (DA) agonist pramipexole (10-500 microg/kg) showed dose-related effects on wakefulness (W), slow wave sleep (SWS) and REM sleep in rats. The 30 microg/kg dose of the DA agonist increased SWS and REM sleep and reduced W during the first recording hour, while the 500 microg/kg dose augmented W. On the other hand, W was increased while SWS and REMS were decreased after the 500 microg/kg dose during the second recording hour. The mixed D2- and D3 receptor antagonist YM-09151-2 (30-500 microg/kg), which per se affected sleep variables prevented the increase of REMS induced by pramipexole. Furthermore, the highest doses (500-1000 microg/kg) of the DA antagonist effectively antagonized the increase of W and reduction of SWS induced by the 500 microg/kg dose of the DA agonist. Pramipexole (30-100 microg/kg) induced a decrease of locomotor activity during the 2 h recording period. In addition, the 500 microg/kg dose gave rise to an initial reduction of motor behavior which was reverted 2 h later. Pramipexole (30 and 500 microg/kg) did not significantly affect striatal DA release during the first two hours following drug administration, as measured by microdialysis. It is tentatively suggested that D3 receptor could be involved in the pramipexole-induced increase of sleep and reduction of locomotor activity. On the other hand, the increase of W and of motor behavior after relatively high doses could be related to activation of postsynaptic D2 receptor.

Sleep and waking during acute histamine H3 agonist BP 2.94 or H3 antagonist carboperamide (MR 16155) administration in rats.

The present study evaluated the effects of histamine H3 receptor agonist BP 2.94 or H3 receptor antagonist carboperamide (MR 16155) given by oral route on sleep and waking in rats surgically prepared for long-term recordings. BP 2.94 produced a significant increase of slow-wave sleep (SWS) that was related to slight decreases of waking, light sleep, and REM sleep. Carboperamide significantly increased waking and decreased SWS and REM sleep. Pretreatment with carboperamide prevented the effect of BP 2.94 on SWS. It is suggested that the effects of BP 2.94 or carboperamide on sleep and waking could depend on changes in the availability of histamine at the postsynaptic H1 receptor. Alternatively, activation or blockade of the H3 heteroreceptors found in the central catecholamine, indolamine, and acetylcholine nerve endings could inhibit or increase the release of noradrenaline, serotonin, dopamine, and acetylcholine. This would secondarily result in changes of sleep variables.

Effects of selective activation of the 5-HT1B receptor with CP-94,253 on sleep and wakefulness in the rat.

The effects of the 5-HT1B receptor agonist CP-94,253 were compared with those of the mixed beta-adrenoceptor and 5-HT1A/B receptor antagonist (+/-)pindolol in rats implanted for chronic sleep recordings. CP-94,253 (5.0-10.0 mg/kg) significantly increased waking and reduced slow wave sleep (SWS) and REM sleep (REMS). At 2.0-4.0 mg/kg (+/-)pindolol reduced REMS. Pretreatment with (+/-)pindolol (2.0-4.0 mg/kg) reversed the effect of CP-94,253 on waking and SWS, while REMS remained suppressed. It is suggested that the 5-HT1B receptor together with other 5-HT receptor subtypes may have a direct regulatory action on sleep and waking in the rat.

Increased waking after intra-accumbens injection of m-chlorophenylbiguanide: prevention with serotonin or dopamine receptor antagonists.

Bilateral injection of the selective 5-HT3 receptor agonist m-chlorophenylbiguanide (5.0-40.0 micrograms) into the nucleus accumbens of the rat significantly increased waking and decreased slow wave sleep. Rapid eye movement (REM) sleep remained unchanged. Pretreatment with the 5-HT3 receptor antagonist MDL 72222 (1aH,3a,5a, H-tropan-3-yl-3,5-dichloro-benzoate) (0.5 mg/kg s.c.) reversed the effects of m-chlorophenylbiguanide (10.0-20.0 micrograms) on sleep and waking. Blockade of the dopamine D1 or D2 receptor with (+)-SCH 23390 (0.25 mg/kg s.c.) or YM-09151-2 (cis-N-(1-benzyl-2-methylpyrrolidin-3-yl)-5-chloro-2-methoxy-4- methylaminobenzamide) (0.5 mg/kg s.c.), respectively antagonized the increase of waking and reduction of slow wave sleep induced by m-chloro-phenylbiguanide (10.0 micrograms). Our results tend to indicate that the increase of wakefulness after injection of the selective 5-HT3 receptor agonist m-chlorophenylbiguanide into the nucleus accumbens is partly related to the release of endogenous dopamine. In addition, they suggest that concomitant stimulation of both accumbens dopamine D1 and D2 receptor-related mechanisms is a necessary prerequisite to increase wakefulness.

The effects of selective activation of the 5-HT3 receptor with m-chlorophenylbiguanide on sleep and wakefulness in the rat.

The effects of the 5-HT3 receptor agonist, m-chlorophenylbiguanide, were compared with those of the 5-HT3 receptor antagonist, MDL 72222, in rats implanted with electrodes for chronic sleep recordings. m-Chlorophenylbiguanide (12.5-50.0 micrograms) injected into the left lateral ventricle increased wakefulness and rapid eye movement (REM) sleep latency, whereas slow wave sleep, REM sleep and the number of REM periods were reduced. MDL 72222 (0.1-1.0 mg/kg, s.c.) induced a delayed and dose-dependent increase of slow wave sleep. Pretreatment with MDL 72222 (0.1-0.5 mg/kg) prevented the effects of m-chlorophenylbiguanide (50 micrograms) on wakefulness and sleep. It is suggested that the increase of wakefulness after 5-HT3 receptor activation could be related to the release of endogenous serotonin and dopamine.