35 research outputs found

    Analysis of the integration of the three-way catalyst thermal management in the on-line supervisory control strategy of a gasoline full hybrid vehicle

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    Full hybrid electric vehicles have proven to be a midterm viable solution to fulfil stricter regulations, such as those regarding carbon dioxide abatement. Although fuel economy directly benefits from hybridization, the use of the electric machine for propulsion may hinder an appropriate warming of the aftertreatment system, whose temperature is directly related to the emissions conversion efficiency. The present work evaluates the efficacy of a supervisory energy management strategy based on Equivalent Minimization Consumption Strategy (ECMS) which incorporates a temperature-based control for the thermal management of the Three-Way Catalyst (TWC). The impact of using only the midspan temperature of TWC is compared against the case where temperature at three different sampling points along the TWC length are used. Moreover, a penalty term based on TWC temperature has been introduced in the cost functional of the ECMS to allow the control of the TWC temperature operating window. In fact, beyond a certain threshold, the increase of the engine load, requested to speed up TWC warming, does not translate into a better catalyst efficiency, because the TWC gets close to its highest conversion rate. A gasoline P2 parallel full hybrid powertrain has been considered as test case. Results show that the effects of the different calibrations strategies are negligible on the TWC thermal management, as they do not provide any improvements in the fuel economy nor in the emissions abatement of the hybrid powertrain. This effect can be explained by the fact that the charge sustaining condition has a greater weight on the energy management strategy than the effects deriving from the addition of the soft constraints to control the TWC thermal management. These results hence encourage the use of simple setups to deal with the control of the TWC in supervisory control strategies for full hybrid electric vehicle

    Mucopexy-Recto Anal Lifting (MuRAL) in managing obstructed defecation syndrome associated with prolapsed hemorrhoids and rectocele : preliminary results

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    Purpose: Treatment of rectocele associated with prolapsed hemorrhoids is a debated topic. Transanal stapling achieved good midterm results in patients with symptoms of obstructed defecation, nevertheless a number of severe complications have been reported. The aim of this study was to evaluate the safety and efficacy of a new endorectal manual technique in patients with obstructed defecation due to the combination of muco-hemorrhoidal prolapse and rectocele. Methods: Patients enrolled after preoperative obstructed defecation syndrome (ODS) score, defecography and anoscopy were submitted to the novel Mucopexy-Recto Anal Lifting (MuRAL) combined with a modified Block procedure, and followed up by independent observers with digital exploration 3 weeks postoperatively, and digital exploration plus anoscopy at 3, 6, and 12 months. Operative time, hospital stay, numerating rating scale (NRS), ODS, satisfaction scores, and recurrence rate were recorded. Results: Mean operative time was 35.7 minutes. Fifty-six patients completed 1-year follow-up: 7.1% had acute urinary retention, NRS score was < 3 from the third postoperative day, mean time of daily activity resumption was 12 days, none had persistent fecal urgency, 82% declared excellent/good satisfaction score, significant improvement of 6- and 12-month ODS score, no recurrence of rectocele, and 7.1% recurrence of prolapsed hemorrhoids were observed. Conclusion: MuRAL associated with modified Block technique gave no severe complications and resulted in a safe and effective approach to symptomatic rectocele associated with muco-rectal prolapse. Further randomized studies, larger series, and longer follow-up are needed. [Ann Surg Treat Res 2020;98(5):277-282

    Mucopexy-recto anal lifting: a standardized minimally invasive method of managing symptomatic hemorrhoids, with an innovative suturing technique and the HemorPex System®

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    BACKGROUND: Conservative surgery of hemorrhoidal disease is less painful than traditional hemorrhoidectomy, and mucopexy has less risk of serious postoperative complications than stapled hemorrhoidopexy. The aim of this study was to evaluate the safety and effectiveness of a standardized, modified hemorrhoidopexy, named Mucopexy-Recto Anal Lifting (MuRAL) with the HemorPex System (HPS) in patients with symptomatic III and IV degree hemorrhoids. METHODS: Patients were enrolled from May 2013 to Dec 2015 and operated on with the MuRAL technique, based on arterial ligation and mucopexy at 6 locations, using a standardized clockwise/anti-clockwise rotation sequence of the HPS anoscope. Follow-up controls were carried out by independent observers, as follows: a digital exploration 3 weeks after the intervention, digital exploration plus proctoscopy at 3 and 12 months and repeated at a 12 months interval. Patients who did not strictly follow the postoperative controls were excluded from the study. Primary outcome measurement was the recurrence rate. Secondary measurements were: operative time, hospital stay, postoperative pain, postoperative symptoms and satisfaction score. RESULTS: We operated on 126 patients (72 males, mean age 53.9, range 29-83): 87 (69.6%) with III degree and 39 with IV degree hemorrhoids; 13 patients had a MuRAL as a revisional procedure of a previous operation for hemorrhoids. Mean duration of follow-up was 554 days (range 281-1219). Four patients were excluded from the study. One-year recurrence rate was 4.1%. The mean duration of the intervention was 29.5 minutes (range 23-60) and 92 patients (73%) were discharged during the same day of the operation. Pain VAS Score in the first, second and third postoperative day was 3.9, 2.5, and 1.9, respectively. Twenty-two patients (18%), all submitted to spinal anesthesia, had postoperative acute urinary retention. Fecal urgency, observed in 18.8% of patients at the first control, disappeared within one year after the operation. Mean time to return to normal activity was 8 days (range 5 -10). The patient satisfaction scores at one-year follow up were 31.1% excellent, 57.4% good, 7.4% fairly good and 4.1% poor. In patients with III degree hemorrhoids operative time was significantly shorter, postoperative pain better and transient fecal urgency lower than in IV degree patients. In our experience the standardization of MuRAL operation with HPS, turned out to be a safe and effective minimally invasive approach in managing symptomatic III and IV degree hemorrhoids, avoiding the risk of severe complications, with the possibility to perform a redo-MuRAL in the event of recurrence. CONCLUSIONS: In our series up to 88% of the patients reported a good, or excellent one-year satisfaction score. Further comparative randomized studies with longer follow-up period are needed

    Reasons for tooth extractions and related risk factors in adult patients: a cohort study

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    Background: The aimof this studywas to evaluate oral status, the reasons for tooth extractions and related risk factors in adult patients attending a hospital dental practice. Methods: 120 consecutive patients ranging from23 to 91 years in age (mean age of 63.3 - 15.8) having a total of 554 teeth extracted were included. Surveys about general health status were conducted and potential risk factors such as smoking, diabetes and age were investigated. Results: a total of 1795 teeth weremissing after extraction procedures and the mean number of remaining teeth after the extraction process was 16.8 ± 9.1 per patient. Caries (52.2%) was the most common reason for extraction along with periodontal disease (35.7%). Males were more prone to extractions, with 394 of the teeth extracted out of the total of 554 (71.1%). Male sex (β = 2.89; 95% CI 1.26, 4.53; p = 0.001) and smoking habit (β = 2.95; 95% CI 1.12, 4.79; p = 0.002) were related to a higher number of teeth extracted. Age (β = -0.24; 95% CI -0.31, -0.16; p < 0.001) and diabetes (β = -4.47; 95% CI -7.61, -1.33; p = 0.006) were related to a higher number of missing teeth at evaluation time. Moreover, periodontal disease was more common as a reason of extraction among diabetic patients than among non-diabetic ones (p = 0.04). Conclusions: caries and periodontal disease were the most common causes of extraction in a relatively old study population: further screening strategies might be required for the early interception of caries and periodontal disease

    Interleukin-15 is required for immunosurveillance and immunoprevention of HER2/neu-driven mammary carcinogenesis

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    We previously demonstrated that HER2/neu-driven mammary carcinogenesis can be prevented by an interleukin-12 (IL-12)-adjuvanted allogeneic HER2/neu-expressing cell vaccine. Since IL-12 can induce the release of interleukin-15 (IL-15), in the present study we investigated the role played by IL-15 in HER2/neu driven mammary carcinogenesis and in its immunoprevention

    COX7A2L genetic variants determine cardiorespiratory fitness in mice and human

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    Benegiamo et al. identify genetic variants of the mitochondrial supercomplex assembly factor COX7A2L in the skeletal muscle of mice and humans that promote cardiorespiratory fitness.Mitochondrial respiratory complexes form superassembled structures called supercomplexes. COX7A2L is a supercomplex-specific assembly factor in mammals, although its implication for supercomplex formation and cellular metabolism remains controversial. Here we identify a role for COX7A2L for mitochondrial supercomplex formation in humans. By using human cis-expression quantitative trait loci data, we highlight genetic variants in the COX7A2L gene that affect its skeletal muscle expression specifically. The most significant cis-expression quantitative trait locus is a 10-bp insertion in the COX7A2L 3 ' untranslated region that increases messenger RNA stability and expression. Human myotubes harboring this insertion have more supercomplexes and increased respiration. Notably, increased COX7A2L expression in the muscle is associated with lower body fat and improved cardiorespiratory fitness in humans. Accordingly, specific reconstitution of Cox7a2l expression in C57BL/6J mice leads to higher maximal oxygen consumption, increased lean mass and increased energy expenditure. Furthermore, Cox7a2l expression in mice is induced specifically in the muscle upon exercise. These findings elucidate the genetic basis of mitochondrial supercomplex formation and function in humans and show that COX7A2L plays an important role in cardiorespiratory fitness, which could have broad therapeutic implications in reducing cardiovascular mortality.Peer reviewe

    Mutual Antagonism between Circadian Protein Period 2 and Hepatitis C Virus Replication in Hepatocytes.

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    Hepatitis C virus (HCV) infects approximately 3% of the world population and is the leading cause of liver disease, impacting hepatocyte metabolism, depending on virus genotype. Hepatic metabolic functions show rhythmic fluctuations with 24-h periodicity (circadian), driven by molecular clockworks ticking through translational-transcriptional feedback loops, operated by a set of genes, called clock genes, encoding circadian proteins. Disruption of biologic clocks is implicated in a variety of disorders including fatty liver disease, obesity and diabetes. The relation between HCV replication and the circadian clock is unknown. METHODS: We investigated the relationship between HCV core infection and viral replication and the expression of clock genes (Rev-Erbα, Rorα, ARNTL, ARNTL2, CLOCK, PER1, PER2, PER3, CRY1 and CRY2) in two cellular models, the Huh-7 cells transiently expressing the HCV core protein genotypes 1b or 3a, and the OR6 cells stably harboring the full-length hepatitis C genotype 1b replicon, and in human liver biopsies, using qRT-PCR, immunoblotting, luciferase assays and immunohistochemistry. RESULTS: In Huh-7 cells expressing the HCV core protein genotype 1b, but not 3a, and in OR6 cells, transcript and protein levels of PER2 and CRY2 were downregulated. Overexpression of PER2 led to a consistent decrease in HCV RNA replicating levels and restoration of altered expression pattern of a subset of interferon stimulated genes (ISGs) in OR6 cells. Furthermore, in liver biopsies from HCV genotype 1b infected patients, PER2 was markedly localized to the nucleus, consistent with an auto-inhibitory transcriptional feedback loop. CONCLUSIONS: HCV can modulate hepatic clock gene machinery, and the circadian protein PER2 counteracts viral replication. Further understanding of circadian regulation of HCV replication and rhythmic patterns of host-hosted relationship may improve the effectiveness of HCV antiviral therapy. This would extend to hepatic viral infections the current spectrum of chronotherapies, implemented to treat metabolic, immune related and neoplastic diseas

    COX7A2L genetic variants determine cardiorespiratory fitness in mice and human

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    Benegiamo et al. identify genetic variants of the mitochondrial supercomplex assembly factor COX7A2L in the skeletal muscle of mice and humans that promote cardiorespiratory fitness.Mitochondrial respiratory complexes form superassembled structures called supercomplexes. COX7A2L is a supercomplex-specific assembly factor in mammals, although its implication for supercomplex formation and cellular metabolism remains controversial. Here we identify a role for COX7A2L for mitochondrial supercomplex formation in humans. By using human cis-expression quantitative trait loci data, we highlight genetic variants in the COX7A2L gene that affect its skeletal muscle expression specifically. The most significant cis-expression quantitative trait locus is a 10-bp insertion in the COX7A2L 3 ' untranslated region that increases messenger RNA stability and expression. Human myotubes harboring this insertion have more supercomplexes and increased respiration. Notably, increased COX7A2L expression in the muscle is associated with lower body fat and improved cardiorespiratory fitness in humans. Accordingly, specific reconstitution of Cox7a2l expression in C57BL/6J mice leads to higher maximal oxygen consumption, increased lean mass and increased energy expenditure. Furthermore, Cox7a2l expression in mice is induced specifically in the muscle upon exercise. These findings elucidate the genetic basis of mitochondrial supercomplex formation and function in humans and show that COX7A2L plays an important role in cardiorespiratory fitness, which could have broad therapeutic implications in reducing cardiovascular mortality

    Impact of thermal management of the three-way catalyst on the energy efficiency of a P2 gasoline FHEV

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    Gasoline Full Hybrid Electric Vehicles (FHEVs) are considered among good candidates as cost-effective solution to comply with upcoming emissions legislation. However, several studies have highlighted that frequent start-and-stops worsen the hydrocarbon tailpipe emissions, especially when the light-off temperature of the three-way catalyst (TWC) has not been reached. In fact, strategies only addressing the minimization of fuel consumption tend to delay engine activation and hence TWC warming, especially during urban driving. Goal of the present research is therefore to develop an on-line powertrain management strategy accounting also for TWC temperature, in order to reduce the time needed to reach TWC light-off temperature. A catalyst model is incorporated into the model of the powertrain where torque-split is performed by an adaptive equivalent consumption minimization strategy (a-ECMS). The developed a-ECMS operates on a domain of power-split combinations between electric machine and internal combustion engine, which, aside from satisfying the torque demand, also ensure a controlled ICE torque derivative as well as a controlled ICE start-and-stop frequency. Hence, the algorithm, which is extended for TWC thermal management, incorporates a penalty on the deviation of the TWC temperature from its optimal temperature range. The strategy has been tested on a gasoline P2 FHEV platform whose components (internal combustion engine, electric machine, battery and three-way catalyst) have been experimentally characterized. In particular, the battery current limitations have been modelled as a function of energy transfer. The effects deriving from the strategy, in terms of fuel consumption and catalyst efficiency, have been analyzed on the WLTC (Worldwide harmonized Light vehicles Test Cycles), the new homologation cycle enforced by European legislation. The control algorithm enhances a sufficient catalyst heating within a timespan comparable to the one of a conventional ICE case. The control strategy that integrates TWC thermal management causes an increase of about 2% in fuel consumption, compared to an only fuel economy-oriented a-ECMS strategy

    Effect of Incorporating the Thermal Management of the Three-Way Catalyst on Energy Effciency and Tailpipe Emissions for a P2 Parallel Hybrid Vehicle

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    The energy management of hybrid electric vehicles (HEVs) is a complex subject that can be addressed with the tools provided by optimal control theory. Optimization algorithms explored so far in the literature, like dynamic programming (DP) or equivalent consumption minimization strategy (ECMS), have systematically analyzed the potential CO2 reduction for different topologies and degree of hybridization. However, the management of engine and electric machine (EM) neglects that the catalyst material in the aftertreatment system needs to reach a certain temperature to properly convert pollutant emissions. In this study, the thermal management of the catalyst in a gasoline HEV has been investigated, and two algorithms have been proposed. Two strategies based on the ECMS are presented: the first one explicitly considers the catalyst temperature; the second one keeps the underlying structure of ECMS, but it adds a high-level rule to indirectly encompass catalyst management. To have a reliable catalyst temperature, a monodimensional model for the three-way catalyst (TWC), incorporating chemical kinetics, has been implemented. Finally, both strategies have been assessed via numerical simulations on two different driving cycles: the Worldwide harmonized Light vehicles Test Cycle (WLTC) and the Transport for London cycle (TfL), an urban driving cycle that is selected as a worst- case scenario for the thermal management of the aftertreatment system. On the WLTC both strategies show a 2% increase in fuel consumption with a potential 60% NOx reduction. On the urban cycle, only the second strategy is able to ensure the catalyst heating in a reasonable timespan. However general trends are still confirmed: when the catalyst thermal management is incorporated into the energy management strategy, since the first ignition, the engine produces extra power and charges the battery so that the TWC reaches the light-off temperature over a time-lapse comparable with a conventional vehicle. The stored energy is exploited at higher power demands to reduce the fuel consumption. The average engine load is hence shifted upwards in comparison to a fuel economy-oriented strategy
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