110 research outputs found

    Electrical-Loss Analysis of Power-Split Hybrid Electric Vehicles

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    The growing development of hybrid electric vehicles (HEVs) has seen the spread of architectures with transmission based on planetary gear train, realized thanks to two electric machines. This architecture, by continuously regulating the transmission ratio, allows the internal combustion engine (ICE) to work in optimal conditions. On the one hand, the average ICE efficiency is increased thanks to better loading situations, while, on the other hand, electrical losses are introduced due to the power circulation between the two electrical machines mentioned above. The aim of this study is then to accurately evaluate electrical losses and the average ICE efficiency in various operating conditions and over different road missions. The models used in this study are presented for both the Continuously Variable Transmission (CVT) architecture and the Discontinuously Variable Transmission (DVT) architecture. In addition, efficiency maps of the main components are shown. Finally, the simulation results are presented to point out strengths and weaknesses of the CVT architecture

    Calcific lesion preparation for coronary bifurcation stenting

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    Bifurcating coronary lesions are a very common challenge in interventional cardiology because of thetechnical complexity in their treatment, the risk of side branch occlusion and an overall worse outcomewhen compared to non-bifurcating lesions. The presence of calcifications represents further complexity due to the difficulty in device delivery andstent expansion as well as enhanced risk of side branch occlusion. Rotational and orbital atherectomy, scoring and cutting balloons, coronary lithoplasty are available toolswhich have been introduced over the last three decades to overcome such issue. Nevertheless, their application in different contexts of bifurcations presents specific caveats and the studies directed at comparing such techniques have never been expressly oriented in the subset of the bifurcating lesion. In this paper, we review these devices and their usefulness in bifurcations by analyzing consistent datafrom clinical trials, and we propose a practical algorithm for the treatment of severely calcified bifurcatinglesions according to their anatomical features

    Use of contrast-enhanced intraoperative ultrasonography during liver surgery for colorectal cancer liver metastases - Its impact on operative outcome. Analysis of a prospective cohort study

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    Abstract Background Preliminary reports led to discordant conclusions concerning the use of contrast-enhanced intraoperative ultrasonography (CE-IOUS) during surgery for colorectal liver metastases (CLM). The aim of this study was to evaluate the impact of CE-IOUS in patients undergoing surgery for CLM using an advanced preoperative imaging work-up, and well-established reference standards. Materials and methods Forty-seven consecutive patients underwent liver resection using IOUS and CE-IOUS for CLM. All patients underwent preoperative computed tomography (CT) and magnetic resonance imaging (MRI) within 2 weeks prior to surgery. CE-IOUS was performed by injecting intravenously 4.8 ml of sulphur-hexafluoride microbubbles (SonoVue, Bracco, Italy). Reference standards were histology, and 6-month imaging follow-up. Results IOUS discovered 43 additional lesions in 20 patients. CE-IOUS found 10 additional lesions not seen at IOUS in four patients, and confirmed all the IOUS findings. Fourteen CLM in 10 patients appeared within 6 months after surgery. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were, respectively: 66%, 0%, 98%, 0% and 65% for CT + MRI; 88%, 100%, 100%, 8%, 88% for IOUS and 93%, 100%, 100%, 13%, 93% for IOUS + CE-IOUS. In nine patients CE-IOUS afforded better definition of tumour margins thus helping in resection guidance. Conclusions CE-IOUS improves IOUS findings both for detection and for resection guidance. The combination of IOUS and CE-IOUS should be considered routinely in patients operated for CLM

    Primary Aldosteronism and Resistant Hypertension: A Pathophysiological Insight

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    Primary aldosteronism (PA) is a pathological condition characterized by an excessive aldosterone secretion; once thought to be rare, PA is now recognized as the most common cause of secondary hypertension. Its prevalence increases with the severity of hypertension, reaching up to 29.1% in patients with resistant hypertension (RH). Both PA and RH are “high-risk phenotypes”, associated with increased cardiovascular morbidity and mortality compared to non-PA and non-RH patients. Aldosterone excess, as occurs in PA, can contribute to the development of a RH phenotype through several mechanisms. First, inappropriate aldosterone levels with respect to the hydro-electrolytic status of the individual can cause salt retention and volume expansion by inducing sodium and water reabsorption in the kidney. Moreover, a growing body of evidence has highlighted the detrimental consequences of “non-classical” effects of aldosterone in several target tissues. Aldosterone-induced vascular remodeling, sympathetic overactivity, insulin resistance, and adipose tissue dysfunction can further contribute to the worsening of arterial hypertension and to the development of drug-resistance. In addition, the pro-oxidative, pro-fibrotic, and pro-inflammatory effects of aldosterone may aggravate end-organ damage, thereby perpetuating a vicious cycle that eventually leads to a more severe hypertensive phenotype. Finally, neither the pathophysiological mechanisms mediating aldosterone-driven blood pressure rise, nor those mediating aldosterone-driven end-organ damage, are specifically blocked by standard first-line anti-hypertensive drugs, which might further account for the drug-resistant phenotype that frequently characterizes PA patients

    Clinical and Pathological Tools for Predicting Recurrence and/or Metastasis in Patients with Pheochromocytoma and Paraganglioma

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    Pheochromocytomas and paragangliomas are endocrine tumors belonging to the family of neural crest cell-derived neoplasms. They have an extremely variable clinical course, characterized by a non-negligible percentage of relapse and/or metastasis after radical surgery. To date, there are no reliable methods to predict the metastatic potential of these neoplasms, despite several clinical, molecular, and histopathological factors that have been extensively studied in the literature as predictors of the recurrence and/or metastasis in these neoplasms with different performances and results. In this review, we aimed to discuss and analyze the most important clinical and histopathological tools for predicting recurrence risk in patients affected by pheochromocytomas or paragangliomas. Thus, we compared the main available predictive models, exploring their applications in stratifying patients’ risks. In conclusion, we underlined the importance of simple and validated tools to better define disease aggressiveness and establish tailored patients’ treatments and follow-ups

    Prognostic value of normal sodium levels in patients with metastatic renal cell carcinoma receiving tyrosine kinase inhibitors

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    Background: Although serum sodium concentration, particularly hyponatremia, has been shown to be a prognostic marker of survival in metastatic renal cell carcinoma (mRCC), the impact of normal sodium levels has not been investigated. Herein, we investigate the influence of normonatremia in mRCC patients treated with tyrosine kinase inhibitors (TKIs). Materials and methods: For this retrospective study, the clinical and biochemical data of patients treated with first-line TKIs for mRCC were available from seven Italian cancer centers. We collected natremia levels at baseline and first evaluation after treatment excluding patients with sodium levels outside the normal range (<135 or >145 mEq/L). The remaining patients were subdivided into two groups according to the median sodium value: natremia patients with <140 mEq/L (n = 132) and baseline natremia patients with ≥140 mEq/L (n = 185). Subsequently, we analyzed the impact of sodium levels on response rate (RR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). PFS and OS were estimated through the Kaplan–Meier method, and differences between groups were examined by the log-rank test. Univariate and multivariate Cox regression analyses were applied to evaluate the prognostic factors for PFS and OS. Results: Of the 368 patients, 317 were included in the analysis, 73.1% were men, and the median age was 67 years (range 36–89). When comparing patients with baseline natremia ≥140 mEq/L (n = 185) to patients with natremia <140 mEq/L (n = 132), the PFS was 15 vs. 10 months (p < 0.01) and the OS was 63 vs. 36 months, respectively (p = 0.02). On the first evaluation, patients with serum sodium ≥140 mEq/L had longer PFS (15 vs. 10 months, p < 0.01) and OS (70 vs. 32 months, p < 0.01) than patients with levels <140 mEq/L. Moreover, clinical outcomes showed a significant improvement in patients with natremia ≥140 mEq/L compared with patients with levels <140 mEq/L both at baseline and first evaluation: PFS was 19 vs. 11 months (p < 0.01) and OS was 70 vs. 36 months (p < 0.01), respectively. Conclusions: To the best of our knowledge, this is the first study to investigate the impact of normonatremia in mRCC. We found that serum sodium levels <140 mEq/L at baseline and first assessment are independently associated with worse PFS and OS in mRCC patients treated with TKIs in the first-line setting

    SIRM-SIN-AIOM: appropriateness criteria for evaluation and prevention of renal damage in the patient undergoing contrast medium examinations-consensus statements from Italian College of Radiology (SIRM), Italian College of Nephrology (SIN) and Italian Association of Medical Oncology (AIOM)

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    The increasing number of examinations and interventional radiological procedures that require the administration of contrast medium (CM) in patients at risk for advanced age and/or comorbidities highlights the problem of CM-induced renal toxicity. A multidisciplinary group consisting of specialists of different disciplines-radiologists, nephrologists and oncologists, members of the respective Italian Scientific Societies-agreed to draw up this position paper, to assist clinicians increasingly facing the challenges posed by CM-related renal dysfunction in their daily clinical practice.The major risk factor for acute renal failure following CM administration (post-CM AKI) is the preexistence of renal failure, particularly when associated with diabetes, heart failure or cancer.In accordance with the recent guidelines ESUR, the present document reaffirms the importance of renal risk assessment through the evaluation of the renal function (eGFR) measured on serum creatinine and defines the renal risk cutoff when the eGFR is < 30 ml/min/1.73 m2 for procedures with intravenous (i.v.) or intra-arterial (i.a.) administration of CM with renal contact at the second passage (i.e., after CM dilution with the passage into the pulmonary circulation).The cutoff of renal risk is considered an eGFR < 45 ml/min/1.73 m2 in patients undergoing i.a. administration with first-pass renal contact (CM injected directly into the renal arteries or in the arterial district upstream of the renal circulation) or in particularly unstable patients such as those admitted to the ICU.Intravenous hydration using either saline or Na bicarbonate solution before and after CM administration represents the most effective preventive measure in patients at risk of post-CM AKI. In the case of urgency, the infusion of 1.4% sodium bicarbonate pre- and post-CM may be more appropriate than the administration of saline.In cancer patients undergoing computed tomography, pre- and post-CM hydration should be performed when the eGFR is < 30 ml/min/1.73 m2 and it is also advisable to maintain a 5 to 7 days interval with respect to the administration of cisplatin and to wait 14 days before administering zoledronic acid.In patients with more severe renal risk (i.e., with eGFR < 20 ml/min/1.73 m2), particularly if undergoing cardiological interventional procedures, the prevention of post-CM AKI should be implemented through an internal protocol shared between the specialists who treat the patient.In magnetic resonance imaging (MRI) using gadolinium CM, there is a lower risk of AKI than with iodinated CM, particularly if doses < 0.1 mmol/kg body weight are used and in patients with eGFR > 30 ml/min/1.73 m2. Dialysis after MRI is indicated only in patients already undergoing chronic dialysis treatment to reduce the potential risk of systemic nephrogenic fibrosis

    Application of the Meet-URO score to metastatic renal cell carcinoma patients treated with second- and third-line cabozantinib

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    open18Background: The addition of neutrophil-to-lymphocyte ratio (NLR) and bone metastases to the International Metastatic RCC Database Consortium (IMDC) score (by the Meet-URO score) has been shown to better stratify pretreated metastatic renal cell carcinoma (mRCC) patients receiving nivolumab. This study aimed to validate the Meet-URO score in patients receiving cabozantinib to assess its predictivity and prognostic role. Methods: A multicenter retrospective analysis evaluated mRCC patients receiving â©ľsecond-line cabozantinib. NLR, IMDC score and bone metastases were assessed before the start of cabozantinib. The primary endpoint was overall survival (OS). Harrell's c-index was calculated to compare the accuracy of the prediction of the two scores. Results: Overall, 174 mRCC patients received cabozantinib as second and third line (51.7% and 48.3%, respectively) with a median follow-up of 6.8 months. A shorter median overall survival (mOS) was observed for the IMDC poor-risk group, NLR â©ľ3.2 and the presence of bone metastases, while the IMDC intermediate-risk group had a similar mOS to the favourable-risk one. Applying the Meet-URO score, three risk groups were identified: group 1 (55.2% of patients) with a score of 0-3, group 2 (38.5%) with a score of 4-8 and group 3 (6.3%) with a score of 9. Compared to group 1 (mOS: 39.4 months), a statistically significant worse mOS was observed in group 2 (11.2 months) and group 3 (3.2 months) patients, respectively. The Meet-URO c-index score was 0.640, showing a higher discriminative ability than the IMDC score (c-index: 0.568). Conclusion: This analysis showed that the Meet-URO score provides a more accurate prognostic stratification than the IMDC score in mRCC patients treated with â©ľsecond-line cabozantinib besides nivolumab. Moreover, it is an easy-to-use tool with no additional costs for clinical practice (web-calculator is available at: https://proviso.shinyapps.io/Meet-URO15_score/). Future investigations will include the application of the Meet-URO score to the first-line immunotherapy-based combination therapies.openRebuzzi, Sara Elena; Cerbone, Luigi; Signori, Alessio; Santoni, Matteo; Murianni, Veronica; De Giorgi, Ugo; Procopio, Giuseppe; Porta, Camillo; Milella, Michele; Basso, Umberto; Massari, Francesco; Maruzzo, Marco; Iacovelli, Roberto; Battelli, Nicola; Carmisciano, Luca; Banna, Giuseppe Luigi; Buti, Sebastiano; Fornarini, GiuseppeRebuzzi, Sara Elena; Cerbone, Luigi; Signori, Alessio; Santoni, Matteo; Murianni, Veronica; De Giorgi, Ugo; Procopio, Giuseppe; Porta, Camillo; Milella, Michele; Basso, Umberto; Massari, Francesco; Maruzzo, Marco; Iacovelli, Roberto; Battelli, Nicola; Carmisciano, Luca; Banna, Giuseppe Luigi; Buti, Sebastiano; Fornarini, Giusepp

    Application of the Meet-URO score to metastatic renal cell carcinoma patients treated with second- and third-line cabozantinib

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    Background: The addition of neutrophil-to-lymphocyte ratio (NLR) and bone metastases to the International Metastatic RCC Database Consortium (IMDC) score (by the Meet-URO score) has been shown to better stratify pretreated metastatic renal cell carcinoma (mRCC) patients receiving nivolumab. This study aimed to validate the Meet-URO score in patients receiving cabozantinib to assess its predictivity and prognostic role. Methods: A multicenter retrospective analysis evaluated mRCC patients receiving â©ľsecond-line cabozantinib. NLR, IMDC score and bone metastases were assessed before the start of cabozantinib. The primary endpoint was overall survival (OS). Harrell's c-index was calculated to compare the accuracy of the prediction of the two scores. Results: Overall, 174 mRCC patients received cabozantinib as second and third line (51.7% and 48.3%, respectively) with a median follow-up of 6.8 months. A shorter median overall survival (mOS) was observed for the IMDC poor-risk group, NLR â©ľ3.2 and the presence of bone metastases, while the IMDC intermediate-risk group had a similar mOS to the favourable-risk one. Applying the Meet-URO score, three risk groups were identified: group 1 (55.2% of patients) with a score of 0-3, group 2 (38.5%) with a score of 4-8 and group 3 (6.3%) with a score of 9. Compared to group 1 (mOS: 39.4 months), a statistically significant worse mOS was observed in group 2 (11.2 months) and group 3 (3.2 months) patients, respectively. The Meet-URO c-index score was 0.640, showing a higher discriminative ability than the IMDC score (c-index: 0.568). Conclusion: This analysis showed that the Meet-URO score provides a more accurate prognostic stratification than the IMDC score in mRCC patients treated with â©ľsecond-line cabozantinib besides nivolumab. Moreover, it is an easy-to-use tool with no additional costs for clinical practice (web-calculator is available at: https://proviso.shinyapps.io/Meet-URO15_score/). Future investigations will include the application of the Meet-URO score to the first-line immunotherapy-based combination therapies
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