MSWIFA and cement cooperate in the disposal of soft soil - experimental study on silty sand and silty clay.

Municipal solid waste incineration fly ash (MSWIFA) can be reused as a positive additive to strengthen soft soil. In this study, MSWIFA was initially used as a supplementary solidification material in combination with ordinary Portland cement to prepare fly ash cement-stabilized soil (FACS) with silty sand and silty clay, respectively. The ratio of MWSIFA to total mass was 5%, 10%, and 15%, and the cement content was set as 10% and 15%. The mechanical properties of FACS were evaluated by unconfined compressive strength test. The heavy metal-leaching test was conducted to estimate the environmental risk of FACS. The scanning electron microscope was used to test the micro-structure of FACS. The X-ray diffraction was performed to analyze material composition of FACS. The result indicates that the collaborative solidification of soft soil with MSWIFA and cement is feasible. Regarding the silty clay, the FA had positive effects on the silty clay in the service age (between 50 and 100% with 15% MSWIFA), as the MSWIFA reformulated the initial silty clay structure, resulting in interconnection and pore fill between particles. It can be founded that C-S-H and ettringite are the main products of MSWIFA and cement hydration, which are formed by the hydration of C3S and C2S. Regarding the silty sand, the MSWIFA decreased the peak strength (between 35 and 48% with 15% MSWIFA) but increased the ductility of the stabilized cement. Under the same mix proportions, the leaching toxicities of Zn and Pb in FACS of silty clay were obviously lower than were those of silty sand. Generally, the leaching concentrations of tested metals under all the mix proportions were well below the limit value set by GB 18598-2019 for hazardous waste landfill. Thus, the reuse of MSWIFA in cement-stabilized soil would be one of the effective methods in soft soil treatment and solid waste reduction.

[Mixed craniopharyngioma: long-term results after gamma knife combined with stereotactic brachytherapy].

OBJECTIVE: To evaluate the long-term results of combination treatment with Gamma Knife radiosurgery and stereotactic intracavitary brachytherapy for mixed cystic and solid craniopharyngiomas. METHODS: Sixty-seven consecutive patients with mixed cystic and solid craniopharyngioma treated by Gamma Knife radiosurgery combined with stereotactic brachytherapy from October 1996 to December 2005 were selected for retrospective analysis. The inclusion criterion was the patients who survived for at least 5 years after combined treatment. There were 39 male and 28 female patients and the mean age was 31.5 years (ranged from 3 to 70 years). The clinical evaluations including neurological, neuro-ophthalmological, and neuro-endocrinological examinations, assessment of comprehensive quality of life and neuroimaging examinations were performed periodically. The actuarial survival rates and the mean survival time were calculated by using Kaplan-Meier product limit method. The rates were compared using the χ(2) test. RESULTS: Follow-up period varied from 60 to 168 months, with an average of 114 months. The tumor response rate gained from combination treatment with Gamma Knife radiosurgery and stereotactic intracavitary brachytherapy for predominantly solid and cystic craniopharyngiomas were 10/12 and 90.9% respectively, and 89.6% in all. Mean survival after combination treatment was (110 ± 9) months. The mean survival of patients with predominantly solid and cystic craniopharyngioma were (97 ± 12) months and (120 ± 14) months and the actuarial 10-year survival rates were 7/12 and 69.1%. There was no statistics difference in tumor response rate and 10-year survival rate between 2 groups of patients with predominantly solid and cystic craniopharyngioma. The actuarial 5-, 6-, 7-, 8-, 9- and 10-year survival rates were 90.5%, 85.7%, 83.3%, 76.4%, 69.4% and 60.0% respectively. The decreased visual acuity had improved in 68.3% at 6 months postoperatively and in 70.0% in long term results. Comprehensive quality of life in long term follow-up of 67 patients was excellent in 28 cases(41.8%), good in 19 cases(28.4%), fair in 17 cases(25.4%) and poor in 3 cases(4.5%), respectively. The side effects that occurred 6 to 12 months after treatment were worsening of visual acuity (4 patients), dysfunction of hypothalam (4 patients) and third nerve palsy was found in 1 patents 5 years after treatment. The rate of complications was 13.4%. CONCLUSION: Combination treatment with Gamma Knife radiosurgery and stereotactic intracavitary brachytherapy is highly effective and safety in the treatment of mixed cystic and solid craniopharyngiomas.

[Complications following gamma knife radiosurgery].

OBJECTIVE: To investigate complication features following gamma knife radiosurgery (GKR), and to assess factors causing complications. METHODS: A retrospective analysis was conducted for 253 patients with intracranial arteriovenous malformation (AVMs), meningiomas, glial neoplasms, germinomas and metastatic cancer, respectively, which were treated with GKR.The incidences of acute, subacute and late complications following GKR were evaluated. Meanwhile, risk factors inducing subacute complications, such as the cell proliferative population of target tissues and location of target in AVM and meningioma, were evaluated, respectively. RESULTS: The subacute complications are the prominent reactions in all the five diseases. There is a significant difference in the incidence rate of subacute complications between early responding tissues and slow responding tissues, central and peripheral AVM, basal and non-basal meningioma. CONCLUSIONS: Subacute complications are the prominent reactions after GKR, and the reactions are almost always reversible. The risk of subacute complications following GKR treatment is correlated to the proliferative cell population in the target tissues and the target location (AVM, meningioma).