Search

Inflammatory myofibroblastic tumor (IMT) is a rare tumor with an indolent course. It is less often reported as a second tumor that occurs after treatment of malignant tumors in pediatric patients. Here, we report a case of IMT following Wilms tumor (WT), and conduct a literature review concerning IMTs and WT to evaluate the diagnostic possibility of IMT as a second tumor. The coexistence of the 2 tumors may cause confusion as to whether they share genetic links or that IMTs may appear as late effects of the treatment of WT. [ABSTRACT FROM AUTHOR]

Purpose: To present the clinicopathological characteristics and outcome of children with bladder and ureteral inflammatory myofibroblastic tumors (IMTs) in our center.Methods: We reviewed the medical records of patients with bladder and ureteral IMTs from 2010 to 2018. We recorded patients' demographic data, presentation, hemoglobin level, presence of hydronephrosis, tumor size, treatment, and outcomes.Results: Eight patients with bladder IMTs and 3 with ureteral IMTs were treated at our center during this period. The mean age was 7.1 years. Four patients presented with anemia at diagnosis with the mean hemoglobin level 84.5 g/L. Among patients with bladder IMTs, 5 were male and 3 were female. The most common symptom was lower urinary symptoms in 6 patients, followed by hematuria in 4 patients. 2 patients had complications of hydronephrosis and hydroureter. Among patients with ureteral IMTs, 2 were male and one was female. The most common symptom was abdominal pain, and 3 patients presented with upper urinary tract dilation. All patients underwent surgery. A total of 81.8% were positive for anaplastic lymphoma kinase. Cytokeratin (CK) expression was present in all patients with bladder IMTs, while it was negative in 2 patients with ureteral IMTs. During mean follow-up of 43.4 months, all patients survived event-free.Conclusion: The presence of hydronephrosis and hydroureter is rare in patients with bladder IMTs. Anemia caused by hematuria should be raised the index of suspicion for IMTs. Children with bladder and ureteral IMTs had excellent prognosis. The expression pattern of CK varied between bladder and ureteral IMTs. [ABSTRACT FROM AUTHOR]

Reperfusion causes undesirable damage to the ischemic myocardium while restoring the blood flow. In this study, we evaluated the effects of dexpramipexole (DPX) on myocardial injury induced by ischemia/reperfusion (I/R) in-vivo and the hypoxia/reoxygenation (HR) in-vitro and examined the functional mechanisms of DPX. DPX protected cells against H/R-induced mitochondrial dysfunction and prevented H/R damage. Both myocardial infarct size and tissue damage due to I/R was reduced upon DPX treatment. We discovered that DPX enhanced mitophagy in-vivo and in-vitro , which was accompanied by enhanced expression of PINK1 and Parkin. Knock-down of PINK1 and Parkin by specific siRNAs reversed DPX-induced inhibition of myocardial I/R injury. These findings suggest that DPX might protect against myocardial injury via PINK1 and Parkin. • Dexpramipexole alleviated Hypoxia/Reoxygenation and Ischemia/Reperfusion injury. • Dexpramipexole enhanced mitophagy in vivo and vitro, which was accompanied by enhanced PINK1 and Parkin. • Knock-down of PINK1 and Parkin reversed dexpramipexole-induced inhibition of myocardial ischemic reperfusion injury. [ABSTRACT FROM AUTHOR]

The diesel particulate filter (DPF) is one of the most effective devices for reducing particulate emissions from diesel engines so as to satisfy emission regulations, and it has been widely utilized worldwide. After prolonged operation of the DPF, the accumulated non-combustible ash particulates can be sintered with filter walls and form ash-bridges, which will deteriorate DPF performance and increase emissions. Understanding physicochemical characteristics of ash-bridges is essential for elucidating the generation and evolution mechanisms of ash-bridges. Since lubricant additives are the main source of ash particulates, this study prepared four DPFs containing ash-bridges through accelerate ash loading experiments based on Zn-based, Ca-based, Mg-based, and composite lubricant additives. Subsequently, X-ray computed tomography (X-CT), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were employed to analyze the structural characteristics, micro-morphology, and chemical composition of ash-bridges inside each DPF. The results indicate that Zn-based and composite ashes formed numerous fine ash-bridges in the middle of the DPF, whereas Ca-based and Mg-based ashes resulted in fully shaped and highly blocked ash-bridges. These ash-bridges aggregated into compact ash plugs downstream in all DPFs. The micro-morphology of Zn-based ash-bridges appeared as ball-and-stick, Ca-based ash-bridges aggregated into large ash aggregates in DPF downstream, Mg-based ash-bridges exhibited characteristics of high porosity, and the micro-morphology of composite ash-bridges is spherical in DPF downstream. The primary components of ash-bridges in Zn-based, Ca-based, and Mg-based DPFs are Zn 2 P 2 O 7 , CaSO 4 , and MgO, respectively. The main components of ash-bridges in composite DPF include Ca 7 Mg 2 P 6 O 24 , Zn 3 (PO 4) 2 (H 2 O) 4 , and CaSO 4. These findings provide valuable insights into the understanding of ash-bridges, contributing to the enhancement of DPF performance and durability. • Ash derived from different lubricant additives can form ash-bridges in DPF channels. • The structural characteristics of ash-bridges in the upstream, middle, and downstream of DPF were observed. • The micro-morphologies of ash-bridges from upstream to downstream of DPF center and edge channels were characterized. • The main element and chemical compound of ash-bridges were detected. [ABSTRACT FROM AUTHOR]

• A particulate loading and active regeneration cycle of the diesel particulate filter were performed on a burner. • Most ash-bridges were observed in the middle region of the diesel particulate filter channel. • Using Ca-based or Mg-based additive lubricants is beneficial to reduce the ash-bridge deposition. • When the blockage rate is greater than about 70%, the channels near the ash bridge are destroyed. Diesel particulate filter (DPF), an important after-treatment system, is widely used to trap particulates from diesel engines. After many active regenerations of the DPF, non-volatile ash may form an ash bridge phenomenon in the DPF channel. This paper studies the effects of lubricant components on ash-bridge deposition characteristics in the DPF. Four test lubricants were prepared based on the CK-4 standard lubricant with four different additives (Ca-based, Mg-based, compound, and Zinc dialkyl dithiophosphate (ZDDP) additives), which were separately and proportionately blended into diesel fuel to form four different fuels. A particulate loading and active regeneration cycle of the DPF with those fuels were performed on a burner. The results show that mid-channel ash deposits (MCD) and the ash-bridge phenomenon were observed in the DPF with all four fuels, and the ash-bridge was mainly located in the middle region of the DPF channel. Mg-based or ZDDP additives can improve the ash-channel ratio (A: C) of the MCD. Ca- or Mg-based additives can reduce the distribution density of ash bridges and avoid sintering of DPF. Different shapes of ash bridges will cause different blockage rates in the DPF channel. When the blockage rate of the DPF channel is greater than about 70 %, DPF channels near the ash bridge are destroyed. [ABSTRACT FROM AUTHOR]

As one of the most effective devices to reduce particulate emission from diesel engines, the diesel particulate filter (DPF) has been widely used. However, long-term use of the DPF can cause a large amount of ash to deposit in it, which can significantly affect its performance. In this study, a burner was utilized to deposit ash, derived from four different lubricating oil additives (zinc dialkyl dithiophosphate (Zn-based), calcium sulfonate (Ca-based), magnesium sulfonate (Mg-based), and composite), into four DPFs with the same specification. The four ash-loaded DPFs and a fresh ashless DPF were subsequently tested for active regeneration on an engine bench at the same soot load. The temperature and particulate emission characteristics of the DPFs were measured using thermocouples and a particulate analyzer. The peak regeneration temperature of ash-loaded DPFs moved forward when compared to the fresh DPF, and the peak regeneration temperature of Mg-based DPF reached 694 °C and moved forward to the axial position of 71.5 mm. A low temperature zone appeared at the rear end of edge channels, forming a large temperature gradient up to 75.5 °C/cm. The emission of nucleation-mode particulates at each DPF outlet increased to different degrees during active regeneration, especially for the Zn-based DPF, whose particulate concentration even approached 108 #/cm3. The X-ray computed tomography (X-CT) images of ash-loaded DPFs showed that the distribution of ash in each DPF was quite different, and ash plugs or bridges appeared in the middle and front of some channels, forming a strong blocking effect. It is due to the presence of ash that the soot deposition position moved forward and the wall-flow velocity rose, which increased the local soot density, causing the peak regeneration temperature to rise and move forward. The increase in wall-flow velocity reduced the diffusion filtration efficiency of ash-loaded DPFs, so escaped particulates that were broken up from soot agglomerate burning increased. • Effect of ash derived from lubricant oil additives on DPF were studied. • The peak regeneration temperature of ash-loaded DPFs moved forward. • Abnormal ash deposition resulted in increased particulate emission during active regeneration. • Middle-channel ash plug/bridge is one of the main reasons. [ABSTRACT FROM AUTHOR]