Value of Multi-slice spiral CT in diagnosis of malignant gastrointestinal stromal tumors

Objective： The aim of this study was to investigate the value of multi-slice spiral CT （MSCT） in the diagnosis of malignant gastrointestinal stromal tumors （GISTs）. Methods： Twenty-seven cases of MSCT images of malignant GIST proved by surgery and pathology were retrospectively analyzed. Both plain and enhanced CT scan was performed and multiplanar reconstruction was made in all cases. Results： The lesions originated from the stomach （n = 11）, small intestine （n = 9）, colon （n = 4）, rectum （n = 1）, and mesentery （n = 2）. The transverse diameters of mass were 4.2-22 cm, the edges clearly （n = 12）, unclearly （n = 15）. The mass were mainly irregular in shape Iobulated （n = 19）. The lesions were mainly heterogeneity on plain scan, moderate to marked enhancement in arterial phase and durative enhanced in venous phase. Cystic necrosis were observed in all the lesions, 9 cases were cystic and solid mixed mass. Hepatic metastases （n = 4）, pulmonary metastasis （n = 1）, lymphatic metastasis （n = 2） were detected. The accuracy rate of MSCT diagnosis for location and pathologic features of GISTs were 85.2% （23/27） and 77.8% （21/27）. Conclusion： Two-phase MSCT examination and axial images combined with multiplanar reconstruction images have important value for diagnosis of malignant GIST.

Preparation and selection of Fe-Cu sorbent for COS removal in syngas

A series of iron-based sorbents prepared with iron trioxide hydrate,cupric oxide by a novel method was studied in a fixed-bed reactor for COS removal from syngas at moderate temperature.In addition,the sorbents mixed with various additives in different ratios were tested.The effects of additive type and ratio on the breakthrough capacity and desulfurization performance,as well as the influence of operating conditions on sulfidation behavior of the sorbent,were investigated.The simulate gas contained 1%COS,5%CO_(2),20%-30%CO and 60%-70%H_(2).The outlet gases from the fixed-bed reactor were automatically analyzed by on-line mass spectrometry,and the COS concentration before breakthrough can be kept steady at 1 ppmv.The result shows that the breakthrough sulfur capacity of the sorbent is as high as 25 g-S/100 g.At 700 K and space velocity of 1000 h^(-1),the efficiency of sulfur removal and breakthrough sulfur capacity of the sorbent increase with the increase of copper oxide with an optimum value.The result shows that the species and content of additives also affect desulfurization performance of the sorbent.