This work is devoted to the study of microstructure, corrosion behavior, and deposition formation of ERNiCrMo-13 and NiCrBSi coatings in simulated coal-fired boiler environments. It was found that ...these coatings applied to TP347 boiler steel by means of arc spraying were comprised of Cr1.12Ni2.88 compound. The hot corrosion tests were performed in simulated flue gases and synthetic fly ashes at 900 °C. The composition (wt%) of synthetic ashes was 75 fly ash + (25 − x) Na2SO4 + x NaCl with varying levels of Na2SO4 and NaCl (x = 0, 3.25, 7.99, and 25). The experimental results showed that NiCrBSi coatings had better corrosion resistance than ERNiCrMo-13 coatings. The corrosion kinetic of the coatings was composed of two stages including a rapid mass gain and a reduction of the mass gain rate due to selective oxidation (stage I) and a mass loss or a larger mass gain rate due to dissolving of oxide scales or deposition of fly ashes (stage II). The high level of NaCl in the fly ashes was responsible for the non-parabolic rate law of the corrosion kinetics, the accelerated corrosion of the coatings, and the internal oxidation of the substrates. The severe corrosion of ERNiCrMo-13 and NiCrBSi coatings occurred in the condition with a high content of NaCl. During corrosion tests, the different compounds such as NiO, Cr2O3, CrO2, NiSi2, and Fe3Cr2Si3O12 were formed on the coating surfaces. The protective Cr2O3 and/or CrO2 scales formed due to the selective oxidation acted as a corrosion barrier in the initial stage, and will lose the protection when the reaction between chromium oxides and NaCl occurs. The oxides and salts were found to be covered on the coatings due to the deposition of the fly ashes. The mechanisms of deposition formation, Cl-induced corrosion, and internal oxidation under the simulated coal-fired boiler conditions are discussed.
•Selective oxidation, dissolving of oxide scales, and deposition of fly ashes were found during the corrosion of coatings.•The high level of NaCl in the fly ashes was responsible for the accelerated corrosion and the internal oxidation.•NiCrBSi coating performed better corrosion resistance than ERNiCrMo-13 coating.•NiSi2 and Fe3Cr2Si3O12 formed during the corrosion of coatings under the conditions with high content of NaCl in fly ashes.
Here an inverse gradient structure (IGS) is processed by induction heat treatment on ultrafine-grained substrate, and a multi-gradient structure (MGS) is gained by surface mechanically peening ...treatment on IGS material. The grain size distributions of coarse-ultrafine and nanostructure-coarse-ultrafine gradient from surface to interior are identified in IGS and MGS materials, respectively. Gradient structures maintain reasonable elongation and at the same time display 3–4 times higher yield strength as compared with homogeneous coarse-grained counterpart, indicating improved strength-ductility synergy. Moreover, it is found that the fracture of gradient structures depends largely on the high internal stress caused by the heterogeneous deformation of layers.
Ferroptosis is an iron-dependent form of cell death that is characterized by early lipid peroxidation and different from other forms of regulated cell death in terms of its genetic components, ...specific morphological features, and biochemical mechanisms. Different initiation pathways of ferroptosis have been reported, including inhibition of system X
, inactivation of glutathione-dependent peroxidase 4, and reduced glutathione levels, all of which ultimately promote the production of reactive oxygen species, particularly through enhanced lipid peroxidation. Although ferroptosis was first described in cancer cells, emerging evidence now links mechanisms of ferroptosis to many different diseases, including cerebral ischemia and brain hemorrhage. For example, neonatal brain injury is an important cause of developmental impairment and of permanent neurological deficits, and several types of cell death, including iron-dependent pathways, have been detected in the process of neonatal brain damage. Iron chelators and erythropoietin have both shown neuroprotective effects against neonatal brain injury. Here, we have summarized the potential relation between ferroptosis and neonatal brain injury, and according therapeutic intervention strategies.
In this study, we investigated the value of molecular typing combined with integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) semi-quantitative indices in endometrial ...cancer risk stratification.
A retrospective study was conducted on 86 patients who were pathologically diagnosed with endometrial cancer and underwent surgical treatment after curettage at the Department of Obstetrics and Gynecology, Xuanwu Hospital, Capital Medical University between January 2017 and March 2023. Prior to surgery, each patient underwent integrated PET/MRI examination. The postoperative samples were subjected to pathological diagnosis, immunohistochemistry, and POLE gene sequencing. The differences in clinicopathological features between the four molecular subtypes and the differences in integrated PET/MRI semi-quantitative indexes (SUV max, ADC min) between the four molecular subtypes were analyzed. The cutoff value of molecular typing combined with integrated PET/MRI semi-quantitative indices for endometrial cancer risk stratification was determined.
There were statistically significant differences in pathological types and tumor grades among the four molecular subtypes of endometrial cancer. The values of the four integrated PET/MRI semi-quantitative indices (SUV max and ADC min) of the molecular subtypes were statistically different. The SUV max was greater in the p53abn mutation group than in the POLE mutation group (
< 0.05). The ADC minimum of the POLE mutation group and the MMR-d group was lower than the NSMP group (
< 0.05). Molecular typing combined with the integrated PET/MRI semi-quantitative SUV max index can predict the low/medium risk group of endometrial cancer and the medium-high/high risk group, and the cut-off value of SUV max for predicting the risk of early endometrial cancer was 14.72 (sensitivity 66.7%, specificity 68.7%).
Molecular typing combined with integrated PET/MRI semi-quantitative indicators is useful to achieve risk stratification in patients diagnosed with endometrial cancer and guide individualized treatment.
We conducted imputation to the 1000 Genomes Project of four genome-wide association studies of lung cancer in populations of European ancestry (11,348 cases and 15,861 controls) and genotyped an ...additional 10,246 cases and 38,295 controls for follow-up. We identified large-effect genome-wide associations for squamous lung cancer with the rare variants BRCA2 p.Lys3326X (rs11571833, odds ratio (OR) = 2.47, P = 4.74 × 10(-20)) and CHEK2 p.Ile157Thr (rs17879961, OR = 0.38, P = 1.27 × 10(-13)). We also showed an association between common variation at 3q28 (TP63, rs13314271, OR = 1.13, P = 7.22 × 10(-10)) and lung adenocarcinoma that had been previously reported only in Asians. These findings provide further evidence for inherited genetic susceptibility to lung cancer and its biological basis. Additionally, our analysis demonstrates that imputation can identify rare disease-causing variants with substantive effects on cancer risk from preexisting genome-wide association study data.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Iron is important for a remarkable array of essential functions during brain development, and it needs to be provided in adequate amounts, especially to preterm infants. In this review article, we ...provide an overview of iron metabolism and homeostasis at the cellular level, as well as its regulation at the mRNA translation level, and we emphasize the importance of iron for brain development in fetal and early life in preterm infants. We also review the risk factors for disrupted iron metabolism that lead to high risk of developing iron deficiency and subsequent adverse effects on neurodevelopment in preterm infants. At the other extreme, iron overload, which is usually caused by excess iron supplementation in iron-replete preterm infants, might negatively impact brain development or even induce brain injury. Maintaining the balance of iron during the fetal and neonatal periods is important, and thus iron status should be monitored routinely and evaluated thoroughly during the neonatal period or before discharge of preterm infants so that iron supplementation can be individualized.
In the application of magnetic refrigeration technology, magnetocaloric materials are required to possess large magnetocaloric effect and broad working temperature range with good thermal ...conductivity and mechanical properties. To address this elusive combination of properties, we prepared Ni-Mn-Ga/Al magnetocaloric composites via hot pressing method. Phase composition and element distribution revealed the influence of sintering temperature on composites' microstructure. The magnetic properties and magnetocaloric effect of hot pressed Ni-Mn-Ga alloy and Ni-Mn-Ga/Al composites were studied, indicating their largely broadened working temperature range of 71 K and maximum magnetic entropy change of 2.2–3.0 J/(kg K). Based on thermomagnetic measurements, critical behavior was investigated via modified Arrott plots and Kouvel-Fisher method, and mean-field theory model could best explain the samples' critical behavior. The Ni-Mn-Ga/Al composite also possessed enhanced fracture stress of 306 MPa, much higher than that of bulk Ni-Mn-Ga alloy by arc melting. The good magnetocaloric response of the composites, which is comparable or even better than that of many other Ni-Mn-Ga particle and microwire counterparts, is accompanied by improved thermal conductivity and mechanical properties, extending the applicability of magnetocaloric materials with large specific surface area. The novel findings of this systematic study offer new insights into magnetocaloric composites and provide an approach to reach a significant balance when fulfilling multiple requirements of magnetic refrigeration technology.
Display omitted
•Hot pressed Ni-Mn-Ga/Al was thoroughly studied in view of refrigeration application.•HP samples had good MCE comparable to their counterparts with reduced length scale.•MAP and KF method were used to compute critical exponents and study critical behavior.•Order of phase transition was ascertained by both Banerjee criterion and exponent n.•Thermal conductivity and mechanical properties were improved after making composites.
Here we investigate the microstructure and mechanical properties of gradient-structured 301 stainless steel synthesized by surface mechanical attrition treatment. Microstructure gradient in both ...martensite content and grain size, from nanostructured (NS) surface with high volume fraction of martensite to coarse-grained (CG) austenite interior, is identified in the mechanical gradient surface layer. Gradient samples exhibit excellent strength-ductility synergy due to the structure gradient-induced synergistic hardening and phase transformation induced plasticity (TRIP), i.e., combination of gradient and TRIP effects. Comparative analysis reveals that mechanical gradient can promote the phase transformation process, i.e. encouraging the TRIP effect.
IMPORTANCE: It is unclear whether the weekly recommended amount of moderate to vigorous physical activity (MVPA) has the same benefits for mortality risk when activity sessions are spread throughout ...the week vs concentrated in fewer days. OBJECTIVE: To examine the association of weekend warrior and other patterns of leisure-time physical activity with all-cause and cause-specific mortality. DESIGN, SETTING, AND PARTICIPANTS: This large nationwide prospective cohort study included 350 978 adults who self-reported physical activity to the US National Health Interview Survey from 1997 to 2013. Participant data were linked to the National Death Index through December 31, 2015. EXPOSURES: Participants were grouped by self-reported activity level: physically inactive (<150 minutes per week min/wk of MVPA) or physically active (≥150 min/wk of moderate or ≥75 min/wk of vigorous activity). The active group was further classified by pattern: weekend warrior (1-2 sessions/wk) or regularly active (≥3 session/wk); and then, by frequency, duration/session, and intensity of activity. MAIN OUTCOMES AND MEASURES: All-cause, cardiovascular disease (CVD), and cancer mortality. Statistical analyses were performed in April 2022. RESULTS: A total of 350 978 participants (mean SD age, 41.4 15.2 years; 192 432 50.8% women; 209 432 67.8% Non-Hispanic White) were followed during a median of 10.4 years (3.6 million person-years). There were 21 898 deaths documented, including 4130 from CVD and 6034 from cancer. Compared with physically inactive participants, hazard ratios (HR) for all-cause mortality were 0.92 (95% CI, 0.83-1.02) for weekend warrior and 0.85 (95% CI, 0.83-0.88) for regularly active participants; findings for cause-specific mortality were similar. Given the same amount of total MVPA, weekend warrior participants had similar all-cause and cause-specific mortality rates as regularly active participants. The HRs for weekend warrior vs regularly active participants were 1.08 (95% CI, 0.97-1.20) for all-cause mortality; 1.14 (95% CI, 0.85-1.53) for CVD mortality; and 1.07 (95% CI, 0.87-1.31) for cancer mortality. CONCLUSIONS AND RELEVANCE: The findings of this large prospective cohort study suggest that individuals who engage in active patterns of physical activity, whether weekend warrior or regularly active, experience lower all-cause and cause-specific mortality rates than inactive individuals. Significant differences were not observed for all-cause or cause-specific mortality between weekend warriors and regularly active participants after accounting for total amount of MVPA; therefore, individuals who engage in the recommended levels of physical activity may experience the same benefit whether the sessions are performed throughout the week or concentrated into fewer days.
Large-strain ausforming and low-temperature bainite transformation were carried out in a medium C - Si rich alloy steel on a thermomechanical simulator. Then, temperature–time–transformation curves ...of the bainite transformation after ausforming at different temperatures were obtained by dilatometry. The effects of ausforming on transformation kinetics, microstructure, and hardness of samples were studied. Results show that the entire process of bainite transformation can be accelerated by ausforming. With decreasing ausforming temperature, the transformation rates greatly increased at the initial transformation stage but slightly decreased at the final stage. Compared with non-ausformed sample, not only was the maximum growth rate in the ausformed samples larger, but the maximum growth rate also appeared earlier. In addition, the maximum rate of the ausformed bainite transformation was increased and the time of reaching the maximum rate was shortened with decreasing the ausforming temperature. The effect of ausforming on bainite transformation kinetics depended not only on the ausforming temperature and strain but also on the isothermal transformation temperature. The reduction in transformation time was increased under decreased isothermal transformation temperature. Ausforming refined the bainite plates and increased the fraction of retained austenite formed in the subsequent low-temperature isothermal transformation. Consequently, nanostructured bainite with enhanced hardness was prepared in the medium C - Si rich alloy steel.
PDF
