98 research outputs found
Characterization of Hydrotreated Vegetable Oil (HVO) in a Euro 6 Diesel Engine as a Drop-In Fuel and With a Dedicated Calibration
Renewable fuels can play an important role in achieving future goals of energy
sustainability and CO2 reduction. In particular, hydrotreated vegetable oil (HVO) represents one
of the most promising alternatives to petroleum-derived diesel fuels. Several studies have shown
that conventional diesel engines can run on 100% HVO without significant modifications to the
hardware and control strategies. The current activity has experimentally evaluated the potential
of HVO as a “drop-in” fuel, i.e., without changes to the original baseline calibration, comparing
it to conventional diesel fuel on a 2.3-litre Euro 6 compression ignition engine.
Tests revealed that HVO can significantly reduce engine-out soot (by more than 60%), HC and
CO emissions (by about 40%), compared to diesel, while NOx levels and fuel conversion
efficiency remain relatively unchanged under steady-state warmed-up conditions. The
advantages of HVO proved to be further enhanced when the engine has not yet warmed up.
Using statistical techniques of design of experiments (DoE) at three warmed-up steady-state
operating points, the main engine control parameters were recalibrated to demonstrate that
engine-out emissions can be further optimized with a dedicated calibration
Lemmi traslitterati tra integrazione ed estraneità. Il caso dei russismi nei dizionari italiani
On the production of ancient Egyptian blue: Multi-modal characterization and micronscale luminescence mapping
The ancient pigment Egyptian blue has long been studied for its historical significance; however, recent work has shown that its unique visible induced luminescent property can be used both to identify the pigment and to inspire new materials with this characteristic. In this study, a multi-modal characterization approach is used to explore variations in ancient production of Egyptian blue from shabti statuettes found in the village of Deir el-Medina in Egypt (Luxor, West Bank) dating back to the New Kingdom (18th-20th Dynasties; about 1550-1077 BCE). Using quantitative SEM-EDS analysis, we identify two possible production groups of the Egyptian blue and demonstrate the presence of multiple phases within samples using cluster analysis and ternary diagram representations. Using both macro-scale non-invasive (X-rays fluorescence and multi-spectral imaging) and micro-sampling (SEM-EDS and Raman confocal microspectroscopy) techniques, we correlate photoluminescence and chemical composition of the ancient samples. We introduce Raman spectroscopic imaging as a means to capture simultaneously visible-induced luminesce and crystal structure and utilize it to identify two classes of luminescing and non-luminescing silicate phases in the pigment that may be connected to production technologies. The results presented here provide a new framework through which Egyptian blue can be studied and inform the design of new materials based on its luminescent property
Robotic colorectal cancer surgery. How to reach expertise? a single surgeon-experience
The complexity associated with laparoscopic colorectal surgery requires several skills to overcome the technical difficulties related to this procedure. To overcome the technical challenges of laparoscopic surgery, a robotic approach has been introduced. Our study reports the surgical outcomes obtained by the transition from laparoscopic to robotic approach in colorectal cancer surgery to establish in which type of approach the proficiency is easier to reach. Data about the first consecutive 15 laparoscopic and the first 15 consecutive robotic cases are extracted, adopting as a comparator of proficiency the last 15 laparoscopic colorectal resections for cancer. The variables studied are operative time, number of harvested nodes, conversion rate, postoperative complications, recovery outcomes. Our analysis includes 15 patients per group. Our results show that operative time is significantly longer in the first 15 laparoscopic cases (p = 0.001). A significantly lower number of harvested nodes was retrieved in the first 15 laparoscopic cases (p = 0.003). Clavien Dindo I complication rate was higher in the first laparoscopic group, but without a significant difference among the three groups (p = 0.09). Our results show that the surgeon needed no apparent learning curve to reach their laparoscopic standards. However, further multicentric prospective studies are needed to confirm this conclusion
Endoscopic Treatment of Pilonidal Sinus Disease: State of Art and Review of the Literature
Background: Pilonidal sinus disease (PSD) is a chronic troublesome pathology of the natal cleft of the sacrococcygeal region, with an estimated incidence of 26 cases in every 100,000 inhabitants. The aim of this review is to give a snapshot of the current literature on the endoscopic approach to PSD. Methods: A search on endoscopic treatment of pilonidal disease was performed according to PRISMA guidelines, adopting the following search terms: (pilonidal OR sacrococcygeal) and (endoscopic OR VAAPS OR EPSiT OR minimally invasive OR video-assisted OR video assisted). Results: Thirty-four articles were included in the final analysis, among which 23 were on adults and 11 were on pediatric population. The endoscopic approach is associated with painless postoperative pain, good aesthetic results, short time off work, and high patient satisfaction. Despite these advantages in short-term outcomes, results on recurrence rate in a long-term follow up are needed to definitively confirm the importance of this technique. Conclusions: The endoscopic approach is associated with significant postoperative advantages over other standard surgical approaches, and it should be included in the surgical portfolio for the treatment of PSD. According to the Italian guidelines, this technique could be considered as the gold standard for limited PSD. However, the favorable short-term-outcomes and lack of reliable data on long-term follow-up must be a stimulus to perform further high-quality studies to give definitive conclusions on this technique
Hematological and Genetic Markers in the Rational Approach to Patients With HCV Sustained Virological Response With or Without Persisting Cryoglobulinemic Vasculitis
Background and Aims: Direct-acting antivirals (DAAs) usually lead to improvement/remission of cryoglobulinemic vasculitis (CV), although symptoms may persist/recur after a sustained virological response (SVR). We evaluated hematological and genetic markers in patients with HCV-SVR vasculitis with and without persisting/recurring symptoms to early predict the CV outcome. Approach and Results: Ninety-eight patients with HCV-CV were prospectively enrolled after a DAA-induced SVR: Group A: 52 with complete clinical response; Group B: 46 with symptom maintenance/recurrence. Monoclonal B-cell lymphocytosis, t(14;18) translocation, and abnormal free light chains κ/λ ratios were detected by flow cytometry or nested-PCR or nephelometry in 4% Group A versus 17% Group B (P = 0.04) patients, 17% Group A versus 40% Group B patients (P = 0.02), and 17% Group A versus 47% Group B (P = 0.003) patients, respectively. At least 1 out of 3 clonality markers was altered/positive in 29% of Group A versus 70% of Group B patients (P < 0.0001). When available, pretherapy samples were also tested for t(14;18) translocation (detected in 12/37 [32%] Group A and 21/38 [55%] Group B) and κ/λ ratios (abnormal in 5/35 [14%] Group A and 20/38 [53%] Group B) (P = 0.0006), whereas at least one clonality marker was detected/altered in 16/37 (43%) Group A and 30/38 (79%) Group B (P = 0.002). CV-associated single-nucleotide polymorphisms were tested by real-time PCR. Among them, notch4 rs2071286 T minor allele and TT genotype showed a higher frequency in Group B versus Group A (46% vs. 29%, P = 0.01, and 17% vs. 2%, P = 0.006, respectively). Conclusions: Hematological or genetic analyses could be used to foresee the CV clinical response after DAA therapy and could be valuable to assess a rational flowchart to manage CV during follow-up
Grief-focused cognitive behavioral therapies for prolonged grief symptoms: A systematic review and meta-analysis
Background: Studies suggest that cognitive behavioral therapies (CBTs) may be efficacious in reducing symptoms of prolonged grief disorder (PGD), but no comprehensive overview and pooled estimate of CBTs’ effect on PGD in adulthood exist. We conducted a systematic review and meta-analysis of randomized controlled trials. Method: Studies were selected independently by two researchers based on a systematic literature search in Pubmed, APA PsycInfo, Web of Science, and Embase. Meta-analyses provided pooled effect sizes for the effects of CBTs on PGD symptoms and secondary outcomes. We explored potential moderators of effect, risk of bias of included studies, and evaluated the quality of the meta-analytical evidence through the Grading of Recommendations, Assessment, Development, and Evaluation system. Results: The meta-analysis included 22 studies of 2,602 bereaved adults (averaged study Mage = 49 years). CBTs had a statistically significant medium effect on PGD symptoms at postintervention (K = 22, g = 0.65, 95%CI [0.49, 0.81]), and a large effect at follow-up (K = 7, g = 0.90, 95%CI [0.37, 1.43]). Statistically significant small-tomedium effects were found at postintervention on posttraumatic stress symptoms (K = 10, g = 0.74, 95% CI [0.49, 0.98]), depression (K = 19, g = 0.53, 95%CI [0.36, 0.71]), and anxiety (K = 9, g = 0.35, 95%CI [0.22, 0.49]). The effects on PGD remained unchanged when adjusted for possible outliers. None of the moderator analyses reached statistical significance. Conclusion: This review suggests that CBTs are efficacious in reducing PGD symptoms in adulthood. Generalization of findings should be done with caution due to considerable inconsistency and indirectness of meta-analytic evidence
Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy
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
Crustal and basin evolution of the southwestern Barents Sea: from Caledonian orogeny to continental breakup
A new generation of aeromagnetic data documents the post-Caledonide rift evolution of the southwestern Barents Sea (SWBS) from the Norwegian mainland up to the continent-ocean transition. We propose a geological and tectonic scenario of the SWBS in which the Caledonian nappes and thrust sheets, well-constrained onshore, swing from a NE-SW trend onshore Norway to NW-SE/NNW-SSE across the SWBS platform area. On the Finnmark and Bjarmeland platforms, the dominant inherited magnetic basement pattern may also reflect the regional and post-Caledonian development of the late Paleozoic basins. Farther west, the pre-breakup rift system is characterized by the Loppa and Stappen Highs, which are interpreted as a series of rigid continental blocks (ribbons) poorly thinned as compared to the adjacent grabens and sag basins. As part of the complex western rift system, the Bjørnøya Basin is interpreted as a propagating system of highly thinned crust, which aborted in late Mesozoic time. This thick Cretaceous sag basin is underlain by a deep-seated high-density body, interpreted as exhumed high-grade metamorphic lower crust. The abortion of this propagating basin coincides with a migration and complete reorganization of the crustal extension toward a second necking zone defined at the level of the western volcanic sheared margin and proto-breakup axis. The abortion of the Bjørnøya Basin may be partly explained by its trend oblique to the regional, inherited, structural grain, revealed by the new aeromagnetic compilation, and by the onset of further weakening later sustained by the onset of magmatism to the west
Metastability for Glauber dynamics on the complete graph with coupling disorder
NWOAnalysis and Stochastic
- …