Association between leukocyte telomere shortening and exposure to traffic pollution: a cross-sectional study on traffic officers and indoor office workers

Background: Telomere shortening in blood leukocytes has been associated with increased morbidity and death from cardiovascular disease and cancer, but determinants of shortened telomeres, a molecular feature of biological aging, are still largely unidentified. Traffic pollution has been linked with both cardiovascular and cancer risks, particularly in older subjects. Whether exposure to traffic pollution is associated with telomere shortening has never been evaluated. Methods: We measured leukocyte telomere length (LTL) by real-time PCR in blood DNA from 77 traffic officers exposed to high levels of traffic pollutants and 57 office workers (referents). Airborne benzene and toluene, as tracers for traffic exposure, were measured using personal passive samplers and gas-chromatography/flame-ionization detector analysis. We used covariate-adjusted multivariable models to test the effects of the exposure on LTL and obtain adjusted LTL means and 95% Confidence Intervals (CIs). Results: Adjusted mean LTL was 1.10 (95%CI 1.04-1.16) in traffic officers and 1.27 in referents (95%CI 1.20-1.35) [p < 0.001]. LTL decreased in association with age in both traffic officers (p = 0.01) and referents (p = 0.001), but traffic officers had shorter LTL within each age category. Among traffic officers, adjusted mean relative LTL was shorter in individuals working in high (n = 45, LTL = 1.02, 95%CI 0.96-1.09) compared to low traffic intensity (n = 32, LTL = 1.22, 95%CI 1.13-1.31) [p < 0.001]. In the entire study population, LTL decreased with increasing levels of personal exposure to benzene (p = 0.004) and toluene (p = 0.008). Conclusion: Our results indicate that leukocyte telomere length is shortened in subjects exposed to traffic pollution, suggesting evidence of early biological aging and disease risk

Experimental and numerical study of an automotive component produced with innovative ceramic core in high pressure die casting (HPDC)

Weight reduction and material substitution are increasing trends in the automotive industry. High pressure die casting (HPDC) is the conventional casting technology for the high volume production of light alloys; it has recently found wide application in the manufacturing of critical components, such as complex and thin geometry automotive parts. However, the major restriction of this affordable technology is the difficulty to design and realize hollow sections or components with undercuts. An innovative way to further increase the competitiveness of HPDC is to form complex undercut shaped parts through the use of new lost cores that are able endure the high pressures used in HPDC. This paper investigates the use of innovative ceramic lost cores in the production of a passenger car aluminum crossbeam by HPDC. Firstly, process and structural simulations were performed to improve the crossbeam design and check the technology features. The results led to the selection of the process parameters and the production of some prototypes that were finally characterized. These analyses demonstrate the feasibility of the production of hollow components by HPDC using ceramic cores

Hardening optimization of high chromium-manganese austenitic steel

The study is focused on the assessment of the best thermal range for plastic deformation of Cr-Mn austenitic steel, to obtain a correct hardening and mechanical properties at room temperature. This steel grade is featured by a fully austenitic microstructure deriving from the high concentration of Mn and N, and is mainly used for the retaining rings bearing of power generation shafts. These components should not have magnetic permeability and thus, the mechanical strengthening can be performed by strain hardening and activation of twinning systems during rolling and forging at high temperature. Different specimens were tensile tested at different temperatures and different strains without arriving at the fracture point. Once the strained specimens were cooled, they have been tested by complete tensile tests at room temperature to determine the final mechanical properties. The best combination of the final mechanical properties have been obtained for plastic deformation performed between 250°C and 350°C, but the formation of martensite at 250°C narrows the useful thermal range between 300°C and 350°C. The metallographic observations indicated that the best hardening conditions can be obtained through the exploitation of the twinning plasticity effect and when the deformation temperature avoids any recovery that can reduce the dislocation density maintained after the cooling at room temperature. The performed experimental trials have also allowed stating the most favorable thermal range for the strain hardening of Cr-Mn steels through forging process to maximize the strengthening effect without the detrimental chromium carbide precipitation

Understanding the Role of Ureteral Access Sheath in Preventing Post-Operative Infectious Complications in Stone Patients Treated with Ureteroscopy and Ho:YAG Laser Lithotripsy: Results from a Tertiary Care Referral Center

Introduction and objectives: The use of ureteral access sheaths (UAS) limits the irrigation-induced increase in intrarenal pressure during ureteroscopy (URS). We investigated the relationship between UAS and rates of postoperative infectious complications in stone patients treated with URS. Materials and methods: Data from 369 stone patients treated with URS from September 2016 to December 2021 at a single institution were analyzed. UAS (10/12 Fr) placement was attempted in case of intrarenal surgery. The chi-square test was used to assess the relationship between the use of UAS and fever, sepsis, and septic shock. Univariable and multivariable logistic regression analyses tested the association of patients’ characteristics and operative data and the rate of postoperative infectious complications. Results: Full data collection of 451 URS procedures was available. Overall, UAS was used in 220 (48.8%) procedures. As for postoperative infectious sequalae, we recorded fever (n = 52; 11.5%), sepsis (n = 10; 2.2%), and septic shock (n = 6; 1.3%). Of those, UAS was not used in 29 (55.8%), 7 (70%), and 5 (83.3%) cases, respectively (all p > 0.05). At multivariable logistic regression analysis, performing URS without UAS was not associated with the risk of having fever and sepsis, but it increased the risk of septic shock (OR = 14.6; 95% CI = 1.08–197.1). Moreover, age-adjusted CCI score (for fever-OR = 1.23; 95% CI = 1.07–1.42, sepsis-OR = 1.47; 95% CI = 1.09–1.99, and septic shock-OR = 1.61; 95% CI = 1.08–2.42, respectively), history of fever secondary to stones (for fever-OR = 2.23; 95% CI = 1.02–4.90) and preoperative positive urine culture (for sepsis-OR = 4.87; 95% CI = 1.12–21.25) did emerge as further associated risk factors. Conclusions: The use of UAS emerged to prevent the onset of septic shock in patients treated with URS, with no clear benefit in terms of fever and sepsis. Further studies may help clarify whether the reduction in fluid reabsorption load mediated by UAS is protective against life-threatening conditions in case of infectious complications. The patients’ baseline characteristics remain the main predictors of infectious sequelae in a clinical setting

Extracellular vesicle-packaged miRNA release after short-term exposure to particulate matter is associated with increased coagulation

Background: Exposure to particulate matter (PM) is associated with increased incidence of cardiovascular disease and increased coagulation, but the molecular mechanisms underlying these associations remain unknown. Obesity may increase susceptibility to the adverse effects of PM exposure, exacerbating the effects on cardiovascular diseases. Extracellular vesicles (EVs), which travel in body fluids and transfer microRNAs (miRNAs) between tissues, might play an important role in PM-induced cardiovascular risk. We sought to determine whether the levels of PM with an aerodynamic diameter\ue2\u89\ua410\uce\ubcm (PM10) are associated with changes in fibrinogen levels, EV release, and the miRNA content of EVs (EV-miRNAs), investigating 1630 overweight/obese subjects from the SPHERE Study. Results: Short-term exposure to PM10(Day before blood drawing) was associated with an increased release of EVs quantified by nanoparticle tracking analysis, especially EVs derived from monocyte/macrophage components (CD14+) and platelets (CD61+) which were characterized by flow cytometry. We first profiled miRNAs of 883 subjects by the QuantStudio\ue2\u84\ua2 12K Flex Real Time PCR System and the top 40 EV-miRNAs were validated through custom miRNA plates. Nine EV-miRNAs (let-7c-5p; miR-106a-5p; miR-143-3p; miR-185-5p; miR-218-5p; miR-331-3p; miR-642-5p; miR-652-3p; miR-99b-5p) were downregulated in response to PM10exposure and exhibited putative roles in cardiovascular disease, as highlighted by integrated network analysis. PM10exposure was significantly associated with elevated fibrinogen levels, and five of the nine downregulated EV-miRNAs were mediators between PM10exposure and fibrinogen levels. Conclusions: Research on EVs opens a new path to the investigation of the adverse health effects of air pollution exposure. EVs have the potential to act both as markers of PM susceptibility and as potential molecular mechanism in the chain of events connecting PM exposure to increased coagulation, which is frequently linked to exposure and CVD development