1,104 research outputs found

    Experimental assessment on exploiting low carbon ethanol fuel in a light-duty dual-fuel compression ignition engine

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    Compression ignition (CI) engines are widely used in modern society, but they are also recognized as a significative source of harmful and human hazard emissions such as particulate matter (PM) and nitrogen oxides (NOx). Moreover, the combustion of fossil fuels is related to the growing amount of greenhouse gas (GHG) emissions, such as carbon dioxide (CO2). Stringent emission regulatory programs, the transition to cleaner and more advanced powertrains and the use of lower carbon fuels are driving forces for the improvement of diesel engines in terms of overall efficiency and engine-out emissions. Ethanol, a light alcohol and lower carbon fuel, is a promising alternative fuel applicable in the dual-fuel (DF) combustion mode to mitigate CO2 and also engine-out PM emissions. In this context, this work aims to assess the maximum fuel substitution ratio (FSR) and the impact on CO2 and PM emissions of different nozzle holes number injectors, 7 and 9, in the DF operating mode. The analysis was conducted within engine working constraints and considered the influence on maximum FSR of calibration parameters, such as combustion phasing, rail pressure, injection pattern and exhaust gas recirculation (EGR). The experimental tests were carried out on a single-cylinder light-duty CI engine with ethanol introduced via port fuel injection (PFI) and direct injection of diesel in two operating points, 1500 and 2000 rpm and at 5 and 8 bar of brake mean effective pressure (BMEP), respectively. Noise and the coefficient of variation in indicated mean effective pressure (COVIMEP) limits have been chosen as practical constraints. In particular, the experimental analysis assesses for each parameter or their combination the highest ethanol fraction that can be injected. To discriminate the effect on ethanol fraction and the combustion process of each parameter, a one-at-a-time-factor approach was used. The results show that, in both operating points, the EGR reduces the maximum ethanol fraction injectable; nevertheless, the ethanol addition leads to outstanding improvement in terms of engine-out PM. The adoption of a 9 hole diesel injector, for lower load, allows reaching a higher fraction of ethanol in all test conditions with an improvement in combustion noise, on average 3 dBA, while near-zero PM emissions and a reduction can be noticed, on the average of 1 g/kWh, and CO2 compared with the fewer nozzle holes case. Increasing the load insensitivity to different holes number was observed

    Pilot Study of a New Mandibular Advancement Device

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    This study was conducted to determine the efficacy of a customized mandibular advancement device (MAD) in the treatment of obstructive sleep apnea (OSA). Eight patients (M = 3; F = 5; mean age = 56.3 ± 9.4) with a diagnosis of OSA confirmed by polysomnography (PSG) were re-cruited on the basis of the following inclusion criteria: apnea-hypopnea index (AHI) > 5, age between 18 and 75 years, body mass index (BMI) < 25, and PSG data available at baseline (T0). All were treated with the new NOA® MAD by OrthoApnea (NOA® ) for at least 3 months; PSG with NOA in situ was performed after 3 months of treatment (T1). The following parameters were calculated at T0 and T1: AHI, supine AHI, oxygen desaturation index (ODI), percentage of recording time spent with oxygen saturation <90% (SpO2 < 90%), and mean oxygen desaturation (MeanSpO2%). Data were submitted for statistical analysis. The baseline values were AHI = 21.33 ± 14.79, supine AHI = 35.64 ± 12.80, ODI = 17.51 ± 13.5, SpO2 < 90% = 7.82 ± 17.08, and MeanSpO2% = 93.45 ± 1.86. Four patients had mild OSA (5 > AHI < 15), one moderate OSA (15 > AHI < 30), and three severe OSA (AHI > 30). After treatment with NOA®, statistically significant improvements in AHI (8.6 ± 4.21) and supine AHI (11.21 ± 7.26) were recorded. OrthoApnea NOA® could be an effective alternative in the treatment of OSA: the device improved the PSG parameters assessed

    A single case report of granular cell tumor of the tongue successfully treated through 445 nm diode laser

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    Oral granular cell tumor (GCT) is a relatively rare, benign lesion that can easily be misdiagnosed. Particularly, the presence of pseudoepitheliomatous hyperplasia might, in some cases, lead to the hypothesis of squamous cell carcinoma. Surgical excision is the treatment of choice. Recurrence has been reported in up to 15% of cases treated with conventional surgery. Here, we reported a case of GCT of the tongue in a young female patient, which was successfully treated through 445 nm diode laser excision. Laser surgery might reduce bleeding and postoperative pain and may be associated with more rapid healing. Particularly, the vaporization effect on remnant tissues could eliminate GCT cells on the surgical bed, thus hypothetically leading to a lower rate of recurrence. In the present case, complete healing occurred in 1 week, and no recurrence was observed after 6 months. Laser surgery also allows the possibility to obtain second intention healing. Possible laser-induced histopathological artifacts should be carefully considered

    Cyclo­linopeptide A methanol solvate

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    Crystals of the title compound, C57H85N9O9·CH4O, the methanol solvate of a nine peptide polypeptide, cyclo-(Pro-Pro-Phe-Phe-Leu-Ile-Ile-Leu-Val), were obtained after separation of the cyclic peptide from flax oil. The cyclo­linopeptide A (CLP-A) mol­ecules are linked in chains along the a axis by N—H⋯O hydrogen bonds. Each methanol O atom is hydrogen bonded to one O atom and two N—H groups in the same CLP-A mol­ecule. There are a total of eight hydrogen bonds in each CLP-A–MeOH unit

    Okadaic acid-Parthenolide combination at subtoxic doses induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells by upregulating PTEN.

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    Retinoblastoma is the most common intraocular malignancy afflicting children. The incidence is higher in developing countries, where treatment is limited and long-term survival rates are low. Vincristine, etoposide, and carboplatin -the agents commonly used in the treatment of retinoblastoma- determine side effects causing significant morbidity to pediatric patients and significantly limiting dosing. Thus, identifying new drugs and molecular targets to facilitate the development of novel therapeutics, and finding natural drug combinations to kill cancer cells by synergistically acting at subtoxic doses, may be a good goal. Here, we investigated the effects of two natural compounds, okadaic acid (OKA) and parthenolide (PN), in human retinoblastoma Y79 cells. We showed that OKA/PN combination at subtoxic doses induces potent synergistic apoptotic effects accompanied by decrease in p-Akt, increase in the stabilized p53 forms and potent decrease in pS166\u2013Mdm2. We also showed the key involvement of PTEN which, after OKA/PN treatment, potently increased before p53, suggesting that p53 activation was under PTEN action. PTEN-knockdown increased p-Akt/ pS166Mdm2 over basal levels and significantly lowered p53, while OKA/PN treatment failed both to lower p-Akt and pS166\u2013Mdm2 and to increase p53 below/over their basal levels respectively. OKA/PN treatment potently increased ROS levels while decreased those of GSH. Reducing cellular GSH by butathionine-sulfoximine treatment significantly anticipated the cytotoxic effect exerted by OKA/PN. The effects of OKA/PN treatment on both GSH content and cell viability were less pronounced in PTEN silenced cells than in control cells. Our study reports for the first time both a synergistic apoptotic action between OKA and PN and the involvement of PTEN as key player in the apoptotic mechanism in human retinoblastoma Y79 cells. The results provide strong suggestion for combined inhibition of the PTEN/Akt/Mdm2/p53 pathway

    Relationship between the prevalence of Dibothriocephalus latus(Cestoda: Diphyllobothriidea) and the load of Escherichia coli: New findings in a neglected fish-borne parasitic zoonosis

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    The sub-Alpine lakes of Switzerland, Italy and France have long been reported as an endemic area of diphyllobothriosis, a parasitic zoonosis aused by Dibothriocephalus latus. With this study, we explored the hypothesis for a relationship between the prevalence of D. latus in Perca fluviatilis and the Escherichia coli load in lake water. To do this, we identified eleven sampling sites in three areas (north, centre and south) of Lake Iseo (north Italy) to determine E. coli load and the prevalence of D. latus in P. fluviatilis. Prevalence and 95% confidence interval (CI) of D. latus infestation ranged from 0% (95% CI: 0.71–0.0) in Sarnico (southern area) to 20% (95% CI: 33.0–11.2) in Pisogne (northern area). There were significant differences in prevalence be-tween the sites (χ2= 31.12; p- value= .0006) and in E. coli load (Kruskal–Wallis test; p- value= .0005). There was decreasing gradient of E. coli load and prevalence of D. latus infestation from north to south. A significant positive correlation (r= .881; p- value= .003) was found between E. coli load and prevalence of D. latus. Also, linear regression showed a significant relationship between E. coli load and prevalence of infestation (R2= .775). Our findings offer an explanation for the link between E. coliload in water and D. latus prevalence. The potential factors in this link are the ef-ficiency of the local wastewater treatment plant, the bathymetric profile of the lake and the life cycle of D. latus, which is mainly affected by light and water temperature.KEYWORDSItaly, Lake Iseo, Perca fluviatilis, prevalence of infestation, wastewater treatment plant, the bathymetric profile of the lake and the life cycle of D. latus, which is mainly affected by light and water temperature

    Aortic dilatation in Marfan syndrome: Role of arterial stiffness and fibrillin-1 variants

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    Objective: Marfan syndrome (MFS) is an autosomal dominant genetic disorder characterized by aortic root dilation and dissection and an abnormal fibrillin-1 synthesis. In this observational study, we evaluated aortic stiffness in MFS and its association with ascending aorta diameters and fibrillin-1 genotype. Methods: A total of 116 Marfan adult patients without history of cardiovascular surgery, and 144 age, sex, blood pressure and heart rate matched controls were enrolled. All patients underwent arterial stiffness evaluation through carotid-femoral pulse wave velocity (PWV) and central blood pressure waveform analysis (PulsePen tonometer). Fibrillin-1 mutations were classified based on the effect on the protein, into 'dominant negative' and 'haploinsufficient' mutations. Results: PWV and central pulse pressure were significantly higher in MFS patients than in controls [respectively 7.31 (6.81-7.44) vs. 6.69 (6.52-6.86)m/s, P=0.0008; 41.3 (39.1-43.5) vs. 34.0 (32.7-35.3)mmHg, P<0.0001], with a higher age-related increase of PWV in MFS (β 0.062 vs. 0.036). Pressure amplification was significantly reduced in MFS [18.2 (15.9-20.5) vs. 33.4 (31.6-35.2)%, P<0.0001]. Central pressure profile was altered even in MFS patients without aortic dilatation. Multiple linear regression models showed that PWV independently predicted aortic diameters at the sinuses of Valsalva (ß=0.243, P=0.002) and at the sinotubular junction (ß=0.186, P=0.048). PWV was higher in 'dominant negative' than 'haploinsufficient' fibrillin-1 mutations [7.37 (7.04-7.70) vs. 6.60 (5.97-7.23)m/s, P=0.035], although this difference was not significant after adjustment. Conclusion: Aortic stiffness is increased in MFS, independently from fibrillin-1 genotype and is associated with diameters of ascending aorta. Alterations in central hemodynamics are present even when aortic diameter is within normal limits. Our findings suggest an accelerated arterial aging in MFS

    Predictors of Postabsorptive Ghrelin Secretion after Intake of Different Macronutrients

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    Abstract Context: Release of ghrelin, a gastrointestinal hormone regulating feeding and energy balance, is blunted in obesity, a condition associated with insulin resistance. Objective: The objective was to identify anthropometric and metabolic predictors of postabsorptive ghrelin secretion. Design: We evaluated ghrelin, insulin, glucose, and leptin secretion overnight and after intake of different macronutrients. Subjects: Ten obese subjects (age, 31.8 ± 2.5 yr; body mass index, 43.4 ± 0.8 kg/m2) and six lean subjects (age, 33.5 ± 2.4 yr; body mass index, 21.8 ± 1.4 kg/m2) participated in the study. Main Outcome Measures: The main outcome measures were resting energy expenditure (REE); fat mass; nighttime approximate entropy (ApEn) and synchronicity (cross-ApEn) of ghrelin, insulin, and leptin; insulin sensitivity by homeostatic model approach insulin-sensitivity (HOMA-S%); postabsorptive area under the curve (AUC); and Δ of ghrelin, insulin, glucose, and leptin after carbohydrate-, lipid-, and protein-rich test meals. Results: Nighttime ApEn scores were higher in obese than lean subjects (P &lt; 0.01). Cross-ApEn revealed a synchronicity between ghrelin-insulin, ghrelin-leptin, and insulin-leptin in both groups. Compared with baseline, ghrelin decreased significantly (P &lt; 0.01) in lean and obese subjects after carbohydrates (42.2 vs. 28.5%; P &lt; 0.05), lipids (40.2 vs. 26.2%; P &lt; 0.01), and proteins (42.2 vs. 26.3%; P &lt; 0.01) devoid of between-meal ghrelin differences. Significant associations occurred between nocturnal ghrelin ApEn and insulin (r = 0.53; P &lt; 0.05), postmeal ghrelin AUCs and REE (r = −0.57; P &lt; 0.05), and HOMA-S% (r = 0.52; P &lt; 0.05), postmeal ghrelin Δ and HOMA-S% (r = 0.60; P &lt; 0.05). REE (β = −0.57; P = 0.02) and ghrelin ApEn (β = −0.62; P = 0.01) were predictors of postmeal ghrelin AUC and Δ, respectively. Conclusions: Obesity determined a decreased orderliness of ghrelin secretion and a relative loss of ghrelin-insulin synchrony. Postabsorptive ghrelin secretion decreased significantly both in obese and lean subjects, was related to insulin sensitivity, and was predicted by energy expenditure and hormone pulsatility

    In human retinoblastoma Y79 cells okadaic acid\u2013parthenolide co-treatment induces synergistic apoptotic effects, with PTEN as a key player.

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    Retinoblastoma is the most common intraocular malignancy of childhood. In developing countries, treatment is limited, long-term survival rates are low and current chemotherapy causes significant morbidity to pediatric patients and significantly limits dosing. Therefore there is an urgent need to identify new therapeutic strategies to improve the clinical outcome of patients with retinoblastoma. here, we investigated the effects of two natural compounds okadaic acid (OKa) and parthenolide (PN) on human retinoblastoma Y79 cells. For the first time we showed that OKa/PN combination at subtoxic doses induces potent synergistic apoptotic effects accompanied by lowering in p-akt levels, increasing in the stabilized forms of p53 and potent decrease in ps166-Mdm2. We also showed the key involvement of PTeN which, after OKa/PN treatment, potently increased before p53, thus suggesting that p53 activation was under PTeN action. Moreover, after PTEN-knockdown p-akt/ ps166Mdm2 increased over basal levels and p53 significantly lowered, while OKa/PN treatment failed both to lower p-akt and ps166-Mdm2 and to increase p53 below/over their basal levels respectively. OKa/PN treatment potently increased ROs levels whereas decreased those of Gsh. Reducing cellular Gsh by l-butathionine-[s,R]-sulfoximine treatment significantly anticipated the cytotoxic effect exerted by OKa/ PN. Furthermore, the effects of OKa/PN treatment on both Gsh content and cell viability were less pronounced in PTeN silenced cells than in control cells. The results provide strong suggestion for combining a treatment approach that targets the PTeN/akt/Mdm2/p53 pathway
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