Browsing by Author "Celebi O."

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Effect of Tocilizumab on Acinetobacter baumannii Lung Infection in an Immunosuppressed Rat Model
(2022-01-01) Celebi D.; Halici Z.; Celebi O.; Akgun N.; Keskin H.; Cinar I.; Halici I.; Cinisli K.T.; Yildirim S.
Our study aimed to investigate effect of tocilizumab on the lung tissue in the presence of Acinetobacter baumannii infection in immunosuppressed rats. A forty-eight female Wistar albino rats were divided equally into eight groups: Group 1: Healthy (H), Group 2: Immunosuppressed (IM), Group 3: Healthy rats given A. baumannii bacteria (H+BAC), Group 4: Immunosuppressed rats given A. baumannii bacteria (IM+BAC), Group 5: Healthy rats given tocilizumab (H+TCZ), Group 6: Immunosuppressed rats given tocilizumab (IM+TCZ), Group 7: Healthy rats given A. baumannii bacteria and tocilizumab (H+BAC+TCZ), Group 8: Immunosuppressed rats given tocilizumab and A. baumannii bacteria (IM+BAC+TCZ). Fourteen days after the immunosuppression of group 2, 4, 6 and 8 with hydrocortisone, group 3, 4, 7 and 8 were A. baumannii was dropped into the trachea. One hour after A. baumannii application, TCZ was administered to Groups 5, 6, 7 and 8. NF-κB, IL-6 and NLRP3 mRNA expressions were decreased in the IM group compared to the healthy group (P<0.05). Although NF-κB, IL-6 and NLRP3 mRNA expression decreased in the IM+TCZ group compared to the healthy group (P<0.05) NF-κB, IL-6 and NLRP3 mRNA expression increased in the H+TCZ group (P<0.05). Despite decreasing cytokines, A. baumannii has been shown to increase infection-related lung injury. This suggests that in patients currently or recently using steroids, tocilizumab may increase organ damage due to opportunistic infection.
Physico-mechanical, thermal insulation and resistance characteristics of diatomite and attapulgite based geopolymer foam concrete: Effect of different curing regimes
(2023-04-10) Kaplan G.; Yavuz Bayraktar O.; Bayrak B.; Celebi O.; Bodur B.; Oz A.; Aydin A.C.
This study investigated the physicomechanical, durability and microstructure characteristics of geopolymer foam concrete (GFC) with a unit weight of less than 1500 kg/m3 produced using attapulgite and diatomite. In the blends, as the main binder was used 10, 20 and 40% attapulgite instead of ground blast furnace slag (GBFS). In addition, 30, 40 and 50 kg/m3 foam were used in the blends. Three alternative curing methods were used on GFC: steam (80 °C), water (∼22 °C), and an oven (80 °C). Thermal curing regimens last 24 h at a temperature of 80 °C. The blends’ porosity ranges from 36.8 to 53.3%, while their levels of water absorption range from 32.5 to 49.4%. Unit weights of hardened GFC samples range from 475 to 1226 kg/m3. On the 28th day, after applying the steam curing to blends with a 30 kg/m3 foam dosage, the compressive strength is greater than 5 MPa. After 900 °C heat treatment (elevated temperature effect), a blend with a foam dosage of 30 kg/m3 and 40% attapulgite produced compressive strengths of greater than 4 MPa. The blends’ depths of water penetration range from 22.1 to 27.8 mm. The drying shrinkage of the blends was increased by adding more foam and attapulgite. GFC's thermal conductivity coefficient varies from 0.134 to 0.354 W/m.K. Increasing the attapulgite and foam decreased the thermal conductivity coefficient. Reaction products such as CASH and NASH gels were observed in SEM examinations. As a result, it has been determined that the most suitable results (In terms of physico-mechanical, thermal insulation and strength Properties) can be obtained if steam curing is applied in blends with 20% attapulgite and 30 kg/m3 foam dosage.