Giant low-grade appendiceal mucinous neoplasm: A case report

BACKGROUND Appendiceal mucinous neoplasm (AMN) is extremely rare. Since the disease does not manifest a characteristic profile of clinical symptoms, it is easy to misdiagnose and still difficult to diagnose without operation. Here, we report a case of low-grade AMN (LAMN) and summarize its clinical features, diagnosis, and treatment. CASE SUMMARY A 63-year-old postmenopausal woman presented with a history of right lower abdominal mass. The patient underwent laparotomy, which showed an appendiceal mucocele originating from the apex of the appendix, and a simple appendectomy was performed. The subsequent histological assessment identified an LAMN with no lymph node involvement and negative surgical margin. The patient received six cycles of chemotherapy after surgery, and to date, more than a year after the surgery, the patient remains in good health. CONCLUSION A unified, standardized, detailed, and accurate pathological diagnosis is needed for LAMN, to facilitate selection of an appropriate surgical plan. In addition, the surgeon should record the details of the tumors in the surgical records in order to facilitate follow-up after surgery.

Comprehensive recovery of lead, zinc, and iron from hazardous jarosite residues using direct reduction followed by magnetic separation

Lead, zinc, and iron were recovered from jarosite residues using direct reduction followed by magnetic separation. The influence of the coal dosage, reduction temperature, and reduction time on the volatilization rates of lead and zinc and the metallization rate of iron were investigated. The results show that the volatilization rates of lead and zinc were 96.97% and 99.89%, respectively, and the iron metallization rate was 91.97% under the optimal reduction roasting conditions of a coal dosage of 25.0 wt% and reduction roasting at 1250°C for 60 min. The magnetic concentrate with an iron content of 90.59 wt% and an iron recovery rate of 50.87% was obtained under the optimum conditions in which 96.56% of the reduction product particles were smaller than 37 μm and the magnetic field strength was 24 k A/m. Therefore, the results of this study demonstrate that recovering valuable metals such as lead, zinc, and iron from jarosite residues is feasible using the developed approach.

Acute respiratory distress syndrome following multiple wasp stings treated with extracorporeal membrane oxygenation:A case report

BACKGROUND It is necessary for clinicians to be aware of a rare but possible acute respiratory distress syndrome(ARDS)complication caused by multiple wasp stings.Severe ARDS has a high mortality rate but no specific pharmacotherapies have been identified to date.This case study presents the first case of severe ARDS caused by multiple wasp stings,treated successfully with extracorporeal membrane oxygenation(ECMO).It also emphasizes the effectiveness of early ECMO treatment for severe ARDS with persistent hypoxemia.CASE SUMMARY A 24-year-old woman was admitted to the emergency department after being stung by more than 10 wasps within a 30-min period,with clinical symptoms of multiple rashes,dizziness,chest tightness,nausea,and vomiting.On the 2nd day of admission,the patient developed progressive dyspnea.The patient was diagnosed with ARDS based on clinical manifestations and lung computed tomography(CT)scan.Because of the progressive dyspnea,the intensive care unit physician performed endotracheal intubation and continued to provide ventilator support,but the patient’s respiratory distress worsened,as indicated by the ratio of arterial partial pressure of oxygen to fraction of inspired oxygen.Veno-venous ECMO was initiated for 6 d.On day 7 of admission,ECMO was stopped.On the 11th day of admission,CT scan of the lungs revealed significant reduction of ground-glass opacities and consolidations.After about 2 wk,the patient recovered completely from ARDS and was discharged to home.At the 2-mo follow-up,the patient was in good health with no recurrence of dyspnea nor chest tightness.CONCLUSION ARDS complication caused by multiple wasp stings may be fatal when mechanical ventilation becomes dangerous due to persistent hypoxemia and despite optimization of ARDS management.We propose that the early implementation of ECMO is a relatively effective treatment,although the evidence is relatively limited.

The applicability of vortex identification methods for complex vortex structures in axial turbine rotor passages

The complex vortex structures in the flow around turbine rotor passages, with weak or strong, large or small vortices, interacting with each other, often generate most of aerodynamic loss in turbomachines. Therefore, it is important to identify the vortex structures accurately for the flow field analysis and the aerodynamic performance optimization for turbomachines. In this paper, by using 4 vortex identification methods (the Q criterion, the Q method, the Liutex method and the Q -Liutex method), the vortices are identified in turbine rotor passages. In terms of the threshold selection, the results show that the D method and the Q -Liutex method are more robust, by which strong and weak vortices can be visualized simultaneously over a wide range of thresholds. As for the display consistency of the vortex identification methods and the streamlines, it is shown that the Liutex method gives results coinciding best with the streamlines in identifying strong vortices, while the Q -Liutex method gives results the most consistent with the streamlines in identifying weak vortices. As to the relationship among the loss, the vortices and the shear, except for the Q criterion, the other three methods can distinguish the vortical regions from the high shear regions. And the flow losses in turbine rotor passages are often related to high shear zones, while there is a small loss within the core of the vortex. In order to obtain the variation of vortices in the turbine rotor passages at different working points, the Liutex method is applied in 2 cases of a turbine with different angles of attack. The identification results show that the strengths of the tip leakage vortex and the upper passage vortex are weaker and the distance between them is closer at a negative angle of attack. This indicates that the Liutex method is an effective method, and can be used to analyze the vortex structures and their evolution in turbine rotor passages.