Fabrication of Ag nanoparticles coated leonardite basalt ceramic membrane with improved antimicrobial properties for DNA cleavage, E. coli removal and antibiofilm effects

Mohammed Saleh,Zelal Isik,Pinar Belibagli,Hudaverdi Arslan,Serpil Gonca,Sadin Özdemir,Nurbolat Kudaibergenov,Alireza Khataee,Nadir Dizge 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

This study aimed to fabricate a novel, low-cost, and environmental-friendly ceramic membrane based onbasalt and leonardite powders via press and sintering methods. The fabricated leonardite basalt ceramicmembrane (LBCM) was coated with silver nanoparticles (AgNPs); to create an antibacterial surface. Thecapabilities of the bare and coated membranes were examined. In this context, water permeabilityreached 554 ± 2.61 and 447 ± 1.21 L/m2hbar for bare LBCM and AgNPs-coated LBCM, respectively. Thefabricated membranes indicated 100% Escherichia coli (E. coli) removal efficiency at a transmembranepressure of 0.5 bar. The solid surface antimicrobial activity of the LBCM and AgNPs-coated LBCM reached26.38% and 100%, respectively. The LBCM and AgNPs-coated LBCM were analyzed for the in-vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant. Accordingly, AgNPs-coated LBCM exhibited higherantioxidant activities than raw LBCM. The scavenging capacity reached 83.91% with AgNPs-coatedLBCM, while only 58.95% was achieved with raw LBCM, indicating that AgNPs-coated LBCM was betterthan bare LBCM from an antioxidant activities perspective. AgNPs-coated LBCM had a deoxyribonucleicacid (DNA) cleavage activity (single-strand DNA cleavage activity at 50 mg/L and double-strand DNAcleavage activity at 100 and 200 mg/L). In contrast, the raw LBCM did not exhibit DNA cleavage activityat any concentration. AgNPs-coated LBCM showed higher antimicrobial activities (minimum inhibitionconcentrations (MICs) were 32 mg/L against Enterococcus faecalis (E. faecalis) and 64 mg/L againstStaphylococcus aureus (S. aureus), Candida tropicalis (C. tropicalis), and Enterococcus hirae (E. hirae)). Thebiofilm inhibition of LBCM and AgNPs-coated LBCM powders was tested against S. aureus andPseudomonas aeruginosa (P. aeruginosa). The maximum S. aureus inhabitations by LBCM and AgNPcoatedLBCM were 60.34% and 99.12%, respectively. The inhabitation of P. aeruginosa increased from52.38% before coating to 96.37% at the end of the coating process. Regarding E.coli microbial cell viabilityinhibition, LBCM powders and AgNPs-coated LBCM powders were found to inhibit E. coli growth by68.35% and 100%, respectively.

Evaluation and comparison of the marginal adaptation of two different substructure materials

Karaman, Tahir,Ulku, Sabiha Zelal,Zengingul, Ali Ihsan,Guven, Sedat,Eratilla, Veysel,Sumer, Ebru The Korean Academy of Prosthodonitics 2015 The Journal of Advanced Prosthodontics Vol.7 No.3

PURPOSE. In this study, we aimed to evaluate the amount of marginal gap with two different substructure materials using identical margin preparations. MATERIALS AND METHODS. Twenty stainless steel models with a chamfer were prepared with a CNC device. Marginal gap measurements of the galvano copings on these stainless steel models and Co-Cr copings obtained by a laser-sintering method were made with a stereomicroscope device before and after the cementation process and surface properties were evaluated by scanning electron microscopy (SEM). A dependent t-test was used to compare the mean of the two groups for normally distributed data, and two-way variance analysis was used for more than two data sets. Pearson's correlation analysis was also performed to assess relationships between variables. RESULTS. According to the results obtained, the marginal gap in the galvano copings before cementation was measured as, on average, $24.47{\pm}5.82{\mu}m$ before and $35.11{\pm}6.52{\mu}m$ after cementation; in the laser-sintered Co-Cr structure, it was, on average, $60.45{\pm}8.87{\mu}m$ before and $69.33{\pm}9.03{\mu}m$ after cementation. A highly significant difference (P<.001) was found in marginal gap measurements of galvano copings and a significant difference (P<.05) was found in marginal gap measurements of the laser-sintered Co-Cr copings. According to the SEM examination, surface properties of laser sintered Co-Cr copings showed rougher structure than galvano copings. The galvano copings showed a very smooth surface. CONCLUSION. Marginal gaps values of both groups before and after cementation were within the clinically acceptable level. The smallest marginal gaps occurred with the use of galvano copings.

Civil society and state relations in Turkey: Opposing trajectories of two Islamist women’s civil society organizations

Özgür Keysan Asuman,Özdemir Zelal 이화여자대학교 아시아여성학센터 2020 Asian Journal of Women's Studies(AJWS) Vol.26 No.3

The Islamic women's civil society organizations (CSOs) in Turkey entered a new phase with the lifting of the headscarf ban, which had long been the focus of Islamic women’s activism against authoritarian gender policies in the country. Based on research conducted in 2012 and 2018 on two Islamist women’s CSOs that have been active here during the last two decades, AKDER (Women’s Rights Organization against Discrimination) and BKP (Capital City Women’s Platform Association), this paper aims to understand these groups and their positions regarding the civil society-state relationship under an altered climate vis-à-vis gender. While AKDER represented a shift from an oppositional to a close relationship with the state from 2012 to 2018 respectively, the BKP in 2018 represented a more conflictual and oppositional stance towards the state compared to 2012. This paper argues that the combined impact of the revocation of the ban and an increasingly authoritarian climate in Turkey has led to a shrinking of space for struggle by the women’s movement in general and for the Islamist women in particular. When the headscarf issue disappeared, the solidarity that prevailed among Islamist women started to weaken and divergences emerged.

Evaluation and comparison of the marginal adaptation of two different substructure materials

Sedat Guven,Veysel Eratilla,Ebru Sumer,Ali Ihsan Zengingul,Sabiha Zelal Ulku,Tahir Karaman 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.3

PURPOSE In this study, we aimed to evaluate the amount of marginal gap with two different substructure materials using identical margin preparations. MATERIALS AND METHODS Twenty stainless steel models with a chamfer were prepared with a CNC device. Marginal gap measurements of the galvano copings on these stainless steel models and Co-Cr copings obtained by a laser-sintering method were made with a stereomicroscope device before and after the cementation process and surface properties were evaluated by scanning electron microscopy (SEM). A dependent t-test was used to compare the mean of the two groups for normally distributed data, and two-way variance analysis was used for more than two data sets. Pearson's correlation analysis was also performed to assess relationships between variables. RESULTS According to the results obtained, the marginal gap in the galvano copings before cementation was measured as, on average, 24.47 ± 5.82 µm before and 35.11 ± 6.52 µm after cementation; in the laser-sintered Co-Cr structure, it was, on average, 60.45 ± 8.87 µm before and 69.33 ± 9.03 µm after cementation. A highly significant difference (P<.001) was found in marginal gap measurements of galvano copings and a significant difference (P<.05) was found in marginal gap measurements of the laser-sintered Co-Cr copings. According to the SEM examination, surface properties of laser sintered Co-Cr copings showed rougher structure than galvano copings. The galvano copings showed a very smooth surface. CONCLUSION Marginal gaps values of both groups before and after cementation were within the clinically acceptable level. The smallest marginal gaps occurred with the use of galvano copings.

Checkpoint-inhibition in ovarian cancer: rising star or just a dream?

Klaus Pietzner,Sara Nasser,Sara Alavi,Silvia Darb-Esfahani,Mona Passler,Mustafa Zelal Muallem,Jalid Sehouli 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.6

The introduction of checkpoint inhibitors revolutionized immuno-oncology. The efficacy of traditional immunotherapeutics, like vaccines and immunostimulants was very limited due to persistent immune-escape strategies of cancer cells. Checkpoint inhibitors target these escape mechanisms and re-direct the immune system to anti-tumor toxicity. Phenomenal results have been reported in entities like melanoma, where no other therapy was able to demonstrate survival benefit, before the introduction of immunotherapeutics. The first experience in ovarian cancer (OC) was reported for nivolumab, a fully human anti-programmed cell death protein 1 (PD1) antibody, in 2015. While the data are extraordinary for a mono-immunotherapeutic agent and very promising, they do not match up to the revolutionary results in entities like melanoma. The key to exceptional treatment response in OC, could be the identification of the most immunogenic patients. We hypothyse that BRCA mutation could be a predictor of improved response in OC. The underlying DNA-repair-deficiancy should result in increased immunogenicity because of higher mutational load and more neoantigen presentation. This hypothesis was not tested to date and should be subject to future trials. The present article gives an overview of the immunologic background of checkpoint inhibition (CI). It presents current data on nivolumab and other checkpoint-inhibitors in solid tumors and OC specifically and depicts important topics in the management of this novel substance group, such as side effect control, diagnostic PD-1/programmed cell death-ligand 1 (PD-L1) expression assessment and management of pseudoprogression.