28 research outputs found

    Non-ideal effects on the typical trailing edge shock pattern of ORC turbine blades

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    Abstract At the trailing edge of supersonic high-pressure turbine vanes, a typical shock pattern, the so-called fish-tail shocks, originates due to the flow rotation imposed by its finite thickness. In addition, shock and shock/fan systems can arise in case of a post-expanded channel design or at off-design conditions. ORC turbine stator blades are particularly prone to this phenomena since they are designed to provide a high outlet Mach number, especially at the first stage. In the close proximity of the saturation curve, near the critical point, molecularly complex organic fluids for ORC applications may exhibit a number of non-ideal gasdynamic effects, including a remarkable dependency of the shock properties on the upstream thermodynamic state of the fluid, at a fixed upstream Mach number. The influence of thermodynamic conditions on the shock pattern is assessed as a function of the flow deviation and compared against the ideal gas case, for which the shock properties depends on the upstream Mach number only. Non-ideal effects are investigated here using siloxane vapor MDM (Octamethyltrisiloxane, C 8 H 24 O 2 Si 3 ), as an exemplary organic fluid. The present results can be arguably extended to most vapors currently employed in ORC applications

    Gravitational waves Ă—\times HI intensity mapping: cosmological and astrophysical applications

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    Two of the most rapidly growing observables in cosmology and astrophysics are gravitational waves (GW) and the neutral hydrogen (HI) distribution. In this work, we investigate the cross-correlation between resolved gravitational wave detections and HI signal from intensity mapping (IM) experiments. By using a tomographic approach with angular power spectra, including all projection effects, we explore possible applications of the combination of the Einstein Telescope and the SKAO intensity mapping surveys. We focus on three main topics: \textit{(i)} statistical inference of the observed redshift distribution of GWs; \textit{(ii)} constraints on dynamical dark energy models as an example of cosmological studies; \textit{(iii)} determination of the nature of the progenitors of merging binary black holes, distinguishing between primordial and astrophysical origin. Our results show that: \textit{(i)} the GW redshift distribution can be calibrated with good accuracy at low redshifts, without any assumptions on cosmology or astrophysics, potentially providing a way to probe astrophysical and cosmological models; \textit{(ii)} the constrains on the dynamical dark energy parameters are competitive with IM-only experiments, in a complementary way and potentially with less systematics; \textit{(iii)} it will be possible to detect a relatively small abundance of primordial black holes within the gravitational waves from resolved mergers. Our results extend towards GWĂ—IM\mathrm{GW \times IM} the promising field of multi-tracing cosmology and astrophysics, which has the major advantage of allowing scientific investigations in ways that would not be possible by looking at single observables separately.Comment: 36 pages, 7 figures, 1 tabl

    The Diverticular Disease Registry (DDR Trial) by the Advanced International Mini-Invasive Surgery Academy Clinical Research Network: Protocol for a Multicenter, Prospective Observational Study

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    Diverticular disease is an increasingly common issue, with a variety of clinical presentations and treatment options. However, very few prospective cohort studies explore outcomes between the different presentations and treatments. The Diverticular Disease Registry (DDR Trial) is a multicenter, prospective, observational cohort study on behalf of the Advanced International Mini-Invasive Surgery (AIMS) academy clinical research network. The DDR Trial aims to investigate the short-term postoperative and long-term quality of life outcomes in patients undergoing surgery or medical treatments for diverticular disease. DDR Trial is open to participation by all tertiary-care hospitals. DDR Trial has been registered at ClinicalTriats.gou (NCT 04907383). Data collection will be recorded on Research Electronic Data Capture (REDCap) starting on June 1 , 2021 and will end after 5 years of recruitment. All adult patients with imaging-proven colonic diverticular disease (i.e., symptomatic colonic diverticulosis including diverticular bleeding, diverticulitis, and Symptomatic Uncomplicated Diverticular Disease) will be included. The primary outcome of DDR Trial is quality of life assessment at 12-month according to the Gastrointestinal Quality of Life Index (GIQLI). The secondary outcome is 30-day postoperative outcomes according to the Clavien-Dindo classification. DDR Trial will significantly advance in identifying the optimal care for patients with diverticular disease by exploring outcomes of different presentations and treatments

    APOLLO 11 Project, Consortium in Advanced Lung Cancer Patients Treated With Innovative Therapies: Integration of Real-World Data and Translational Research

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    Introduction: Despite several therapeutic efforts, lung cancer remains a highly lethal disease. Novel therapeutic approaches encompass immune-checkpoint inhibitors, targeted therapeutics and antibody-drug conjugates, with different results. Several studies have been aimed at identifying biomarkers able to predict benefit from these therapies and create a prediction model of response, despite this there is a lack of information to help clinicians in the choice of therapy for lung cancer patients with advanced disease. This is primarily due to the complexity of lung cancer biology, where a single or few biomarkers are not sufficient to provide enough predictive capability to explain biologic differences; other reasons include the paucity of data collected by single studies performed in heterogeneous unmatched cohorts and the methodology of analysis. In fact, classical statistical methods are unable to analyze and integrate the magnitude of information from multiple biological and clinical sources (eg, genomics, transcriptomics, and radiomics). Methods and objectives: APOLLO11 is an Italian multicentre, observational study involving patients with a diagnosis of advanced lung cancer (NSCLC and SCLC) treated with innovative therapies. Retrospective and prospective collection of multiomic data, such as tissue- (eg, for genomic, transcriptomic analysis) and blood-based biologic material (eg, ctDNA, PBMC), in addition to clinical and radiological data (eg, for radiomic analysis) will be collected. The overall aim of the project is to build a consortium integrating different datasets and a virtual biobank from participating Italian lung cancer centers. To face with the large amount of data provided, AI and ML techniques will be applied will be applied to manage this large dataset in an effort to build an R-Model, integrating retrospective and prospective population-based data. The ultimate goal is to create a tool able to help physicians and patients to make treatment decisions. Conclusion: APOLLO11 aims to propose a breakthrough approach in lung cancer research, replacing the old, monocentric viewpoint towards a multicomprehensive, multiomic, multicenter model. Multicenter cancer datasets incorporating common virtual biobank and new methodologic approaches including artificial intelligence, machine learning up to deep learning is the road to the future in oncology launched by this project

    Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

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    IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Current Status Of Salvage Robot-Assisted Laparoscopic Prostatectomy For Radiorecurrent Prostate Cancer

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    Radiation therapy (RT) is one of the treatment options for prostate cancer (PCa). Transperineal low-dose rate brachytherapy (BT) is another safe and effective technique for low-risk PCa. Recurrence after RT for localized PCa can be defined by a PSA value of 2 ng/mL above the nadir after RT, and biochemical recurrence (BCR) rate after RT is 40-60 %. In case of radiorecurrent PCa, treatment options include salvage radical prostatectomy (RP), cryo-therapy, high-intensity focused ultrasound (HIFU), and salvage BT. Only salvage RP has cancer control results for over 10-year follow-up in a substantial portion of patients (30-40 %). However, salvage RP is technically demanding, and experienced surgeons are needed; in fact, RT-induced cystitis, fibrosis, and tissue plane obliteration can lead to significant complications, such as rectal injuries, anastomot-ic stricture, and urinary incontinence. This review describes indications, oncologic and functional outcomes, surgical techniques, and complications of salvage robot-assisted RP. © Springer Science+Business Media, LLC 2012

    Bipolar Transurethral Enucleation of the Prostate: Is it a size-independent endoscopic treatment option for symptomatic benign prostatic hyperplasia?

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    BackgroundBipolar Transurethral Enucleation of the Prostate (B-TUEP) is recommended as a first-choice treatment for benign prostatic obstruction in prostates >80 ml. Differently, B-TUEP is only considered as an alternative option after TURP for smaller prostates (30-80 ml). The aim of our study is to assess the relation between prostate size and surgical outcomes after B-TUEP.MethodsWe performed a retrospective analysis of data collected from 172 patients submitted to B-TUEP. Patients were segregated according to tertiles of prostate volume (PV) (≤60 ml, 61-110 ml, >110 ml). For each group we evaluated enucleation efficacy (enucleated weight/enucleation time), complication rates, urinary and sexual function parameters. Functional and sexual parameters were compared between groups at baseline, 1 and 3 months follow up. Descriptive statistics and linear and logistic regression models tested the association between PV and postoperative complications/outcomes.ResultsOperative time and weight of enucleated adenomas increased along with prostate volumes (all p≤0.01). Enucleation efficacy was higher in men with PV >110 ml compared to other groups (p≤0.001). Length of hospital stay, catheterization time and rates of postoperative complications, such as transfusion and clot evacuation rates and bladder neck/urethral strictures, were comparable between groups. Urinary symptoms improved at 1-and 3-months in each group as compared to baseline evaluation (all pConclusionAccording to our findings, B-TUEP should be considered a "size independent procedure" as it can provide symptom relief in men with prostates of all sizes with the same efficacy and safety profile

    5 year oncological outcomes of the HIGHLOW randomized clinical trial

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    The oncological outcomes of low ligation (LL) compared to high ligation (HL) of the inferior mesenteric artery (IMA) during low-anterior rectal resection (LAR) with total mesorectal excision are still debated. The aim of this study is to report the 5 year oncologic outcomes of patients undergoing laparoscopic LAR with either HL vs. LL of the IMA MATERIALS AND METHODS: Between June 2014 and December 2016, patients who underwent elective laparoscopic LAR + TME in 6 Italian non-academic hospitals were randomized to HL or LL of IMA after meeting the inclusion criteria (HighLow trial; ClinicalTrials.gov Identifier NCT02153801). We analyzed the rate of local recurrence, distant metastasis, overall survival, disease-specific survival, and disease-free survival at 5 years of patients previously enrolled
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