Lightweight Reactive Powder Concrete Containing Expanded Perlite.

This paper presents the test results of the lightweight concrete properties obtained by adding expanded perlite (EP) to an RPC mix in quantities from 30% to 60% by volume of the concrete mix. It has been shown that in these cases it is possible to obtain concrete containing 30% by volume with density of approximately 1900 kg/m3 and the compressive strength > 70 MPa, with a very low water absorption value (3.3%), equal to the water absorption value of RPC without lightweight aggregate (3.3%). However, with the increased quantity of perlite (from 45% to 60%), the concrete density reduction is not observed, as the expanded perlite demonstrates very low resistance to crushing. With the increased amount of perlite, the longer periods of mixing time for all the mix components are required to obtain the homogeneous and fluid concrete mix, what causes grounding down EP. Therefore, using larger quantities of this aggregate in RPC is not recommended. The lightweight RPC shows very good freeze-thaw resistance in the presence of de-icing salt (the scaling mass is lower than 0.1 kg/m2). The above is explained by the compact microstructure of this concrete and the RPC mix location in open pores on the perlite aggregate surface, which consequently affects the strengthening of the aggregate-matrix contact without an interfacial transition zone (ITZ) visible. It has been demonstrated that pozzolanic activity of expanded perlite is much lower than the activity of silica fume and quartz powder, and its impact on increasing the RPC strength is minimal.

Durability of Cement and Ash Mortars with Fluidized and Siliceous Fly Ashes Exposed to HCl Acid Environment over a Period of 2 Years.

The paper presents results of research on the impact of fly ash from fluidized bed combustion (FBC) of lignite, used in quantities of 30 and 45% by mass, and the mixture of FBC and silicious fly ash in amount of 45% by mass, on properties of cement-ash mortars. Mortars were exposed to aggressive environment of 1, 3, and 5% HCl solutions for 2 years. Mortars containing 45% FBC exposed to 1% HCl solution (pH = 2) showed the highest durability from among other mortars. The growth of their strength observed after 90 days of testing in 1% HCl environment, as well as the lowest drop of strength after 730 days of exposure to this environment, resulted from the reduced amount of large pores from 20 to 200 nm in mortars containing fly ash, with simultaneous growth of smaller pores of <20 nm during testing. A beneficial effect has been demonstrated of FBC addition to cement on properties of cement-ash mortars exposed to the aggressive impact of the HCl. Mortars with FBC fly-ash content increased to 45% by mass showed higher strength values, smaller differences in linear and mass changes, and increased durability in an aggressive environment observed during 730 days of testing.

Specificity and sensitivity of INI-1 labeling in epithelioid sarcoma. Loss of INI1 expression as a frequent immunohistochemical event in synovial sarcoma.

INI1 antigen is a product of the INI-1/SMARCB1 gene localized on chromosome 22q. It is well known that INI1 gene inactivation or loss of INI1 antigen expression is observed in epithelioid sarcomas; however, there are only few reports concerning specificity and sensitivity of immunohistochemical INI1 labeling as a marker of this neoplasm. That is why we decided to test 99 soft tissue sarcomas for the presence of the INI1 gene product. More specifically, the analyzed group consisted of 33 synovial sarcomas, 14 fibrosarcomas, 8 desmoid tumors, 8 DFSPs, 5 MPNSTs, 9 epithelioid sarcomas, 11 Ewing sarcomas/PNETs, 9 rhabdomyosarcomas and 2 clear cell sarcomas. Additionally, 7 malignant melanomas and 9 adenocarcinomas were included into the study. Positive staining with an antibody against the INI-1 gene product was observed in all studied cases of MPNST, Ewing sarcoma/PNET, rhabdomyosarcoma, malignant melanoma, clear cell sarcoma, and adenocarcinoma. On the contrary, none of 9 epithelioid sarcomas was labeled. The loss of INI1 expression was also detected in 7 (21.2%) synovial sarcomas, confirmed cytogenetically or by FISH. Considering the lack of reaction with INI-1 antibody as a diagnostic test for epithelioid sarcoma we estimated that its sensitivity reached 100% and specificity - 83.5% (p < 0.0001).

Primary carcinoid tumour in horseshoe kidney.

Primary renal carcinoid tumours are extremely rare. To date, approximately 60 cases have been reported, mostly as case reports with only few series noted. The pathogenesis of this tumour is uncertain because neuroendocrine cells are not found in normal adult renal parenchyma. We report a case of primary renal carcinoid occurring in a horseshoe kidney in a 66-year-old patient. A clinical, histological and immunohistochemical picture of this tumour is presented.