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Objective To study the adsorption capability of chitosan(CTS)for Ni~(2+)in water.Methods The effects of different adsorption time(0-360 min),different temperature(25-60℃)and different initial pH value of the solution(4-8)on the adsorption were investigated.The adsorption kinetics and thermodynamics of CTS for Ni~(2+)in water were also studied and the IR of CTS and CTS-Ni~(2+)were determined.Results The maximal adsorption quantity could reach to 42.15 mg/g in the optimum condition that the temperature is 25℃,pH value was 7.0 and the adsorption time was 4 h.The adsorption kinetics showed that the pseudo-second-order equation was suitable for describing the adsorption of CTS for Ni~(2+)and the related correlation coefficients were more than 0.99.The calculated value of equilibrium adsorption quantity of Ni~(2+)was 45.05 mg/g.Study of adsorption thermodynamics showed that the linear regression equation of lnk and 1/T was lnk=-0.827 7/T+3.416 2,and the correlation coefficient was 0.998 9.The enthalpy change(△H~0)was 6.88 kJ/mol and the entropy change(△S~0)was 28.40 J/(mol?K).The IR showed that the coordination reaction occurred between-NH_2,-OH of CTS and Ni~(2+).Conclusion CTS can effectively remove Ni~(2+) in water.The adsorption of CTS for Ni~(2+)is spontaneous and endothermic.High temperature which is beneficial to the adsorption does not influence the adsorption quantity obviously.
RESUMEN
Objective To study the clinicopathological and immunohistochemical features, histogenesis and biological behavior of solid pseudopapillary tumor of the pancreas ( SPT ). Methods Routine HE and immunohistochemical ( SP) methods were used in 20 cases of SPT. Results There were 18 females and 2 males, age ranging from 13 to 48 years with mean age of 25. 3 years. Abdominal pain and palpable mass were among the main complains. Seventeen cases were followed-up from 9 to 120 monthes. Fourteen cases were alive. Tumors were encapsulated, mixed with solid and cystic tissues. Histological features were psudopapillary structure with a fibrovascular core. Immunohistogically, the tumors were positive for a-1-AT ( 17 cases) , vimentin ( 14 cases) , synaptophysin ( 10 cases) , CgA (5 cases) ,CK and insulin (2 cases) ,glucagon and S-100 (1 case) ,PR (14 cases) , ER (1 case) ,pS2 (6 cases) , but all were negative for CEA and gastrin. Conclusion SPT is of low-graded malignancy and a distinct clinicopathologic entity in young female patients with both exocrine as well as endocrine differentiation. The tumor is closely related with sex hormone receptors.