28 research outputs found

    Poly(dodecyl methacrylate-co-2-(diethylamino)ethyl methacrylate) Gels: Characterization and Solubility Parameters

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    In this work, a copolymer gel with hydrophobic character was synthesized from dodecyl methacrylate (DDMA) and 2-(diethylamino) ethyl methacrylate (DEAEMA) monomers in ethanol at 70 degrees C for 24 h using free radical cross-linking polymerization method. In the synthesis procedure, azobisisobutyronitrile and ethylene glycol dimethacrylate were used as the initiator and cross-linker, respectively. The gel was also prepared in the presence of a pore forming agent (poly(ethylene glycol), PEG) at the same conditions to compare its effect on the swelling and structural/thermal characteristics. The swelling behaviour of the gels was investigated in different solvents and their solubility parameters were found. Solubility parameters of P(DDMA-co-DEAEMA) and P(DDMA-co-DEAEMA)-PEG gels were calculated as 8.2 and 7.7 (cal/cm(3))(1/2), respectively. The gels were characterized by the Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy techniques

    Comparison of mechanical properties and artificial neural networks modeling of PP/PET blends

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    The aim of this study is to show the applicability of artificial neural networks, which are getting more applications with the advancement of technology, to determine the mechanical properties of polymeric materials. Mechanical properties of pure polypropylene, polyethylene terephthalate and their blends are determined in this study and the effect of temperature (room temperature, 40°C and 60°C) on mechanical properties is investigated. The method of artificial neural networks is used to make a prediction for mechanical properties. Mechanical properties of samples are measured using Lloyd 250N capacity tension and compression apparatus at crosshead speed of 10 mm/min, 25 mm/min, and 50 mm/min. For artificial neural networks modelling, the tensile experiment results, temperature, percent ratio, and crosshead speed are used as the input and output parameters. Three-layered multilayer perceptron, feed-forward neural network architecture is used and trained with the error back propagation. The results obtained from the output of the network are compared with the experiment results. The suitability of the method is found to be satisfactory

    New Schiff bases based on isatin and (thio)/carbohydrazone: preparation, experimental–theoretical spectroscopic characterization, and DFT approach to antioxidant characteristics

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    © 2022, The Author(s), under exclusive licence to Springer Nature B.V.In this study, synthesis, spectroscopic elucidation, and investigation of antioxidant properties of new Schiff bases based on isatin and (thio)/carbohydrazone derivatives have been reported for the first time. The structures of the synthesized compounds were elucidated by FT-IR, 1H-NMR, and 13C-NMR spectroscopic methods and elemental analysis. Their DPPH, ABTS, and CUPRAC activities were evaluated as antioxidant properties. Electronic and spectral data of the compounds were obtained by DFT calculations at the B3LYP/6–311+ +G(2d,2p) level of theory. Intramolecular interactions and charge densities on the bonds were analyzed by QTAIM and IRI calculations. In addition to parameters such as frontier molecular orbital energy eigenvalues, electronegativity, nucleophilicity index, and electrodonating power, the changes in the enthalpy of the compounds for the reactions realized through the SET mechanism were calculated to elucidate the antioxidant reactions of the compounds. Most of synthesized compounds exhibited antioxidant activities with the IC50 values ranging from 27.13 to 43.35 µM for DPPH, from 6.47 to 24.96 µM for ABTS and with the A0.50 values ranging from 9.04 to 47.52 µM for CUPRAC. Among them, compound 3, containing two hydroxyl groups, showed the strongest antioxidant activity for each assay (IC50 = 27.13 µM for DPPH, 6.47 µM for ABTS, and A0.50 = 9.04 µM for CUPRAC). The antioxidant activities of compound 3 were almost two or threefold weaker than that of BHA (IC50 = 9.55 µM for DPPH, 3.42 µM for ABTS, and A0.50 = 2.24 µM for CUPRAC), used as a standard. In addition, thiocarbohydrazone compounds exhibited higher antioxidant activity than carbohydrazones. Electron donating ability and single electron transfer enthalpy calculations predicted that thiocarbohydrazone compounds can perform SET reactions more easily than carbohydrazones

    Topluma hizmet uygulamaları dersinde hava kirliliği farkındalığı: Disiplinlerarası bir çalışma

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    The aim of this study is to determine the effect of the interdisciplinary (the disciplines of Turkish, Social Science, Natural Sciences, Mathematics and Public Administration) activities performed in the scope of the Community Service Practices Course on the air pollution awareness (APW). This study has been performed as a multiple case study. Participants consisted of 32 pre-service elementary school teachers and 122 elementary school students enrolled in a 4 th grade. Data were collected using the Air Pollution Awareness Questionnaire, Know-Want-Learn forms and interviews. Content analysis was used for analysis of data. The APW of participants have increased. It has been determined that the pre-service elementary school teachers have evaluated the implementation as being generally successful. Also it has been seen that the implementation has served different purposes out of the study aim for the pre-service elementary school teachers like providing teaching experience and how to teach the interdisciplinary subjects. © 2018, International Electronic Journal of Environmental Education. All rights reserved.20314, EĞTBAP-A-250414-3This study was supported by Scientific Research (Project number: EĞTBAP-A-250414-3, 20314)

    Assessment of prognostic and diagnostic value of some biomarkers in hepatocellular carcinoma

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    © Experimental Oncology, 2020Background: Hepatocellular carcinoma (HCC) is an increasing problem worldwide. Determining a prognosis is important for the management of HCC. Aim: We aimed to investigate the impact of interleukin (IL)-29, galectin-3, leptin, fibronectin and protease-activated receptor-1 on the prognosis and diagnosis of patients with HCC. Materials and Methods: 60 HCC patients (75% male) and 20 healthy volunteers (70% male) were enrolled in this prospective study. Serum samples were obtained during the first admission before any adjuvant or metastatic treatments were administered. Serum biomarkers were determined using ELISA kits. Results: All patients had cirrhosis, and the Child - Pugh stages were as follows: 61.5% Child - Pugh A, 35.9% Child - Pugh B and 2.6% Child - Pugh C (61.7% hepatitis B virus, 11.7% hepatitis C virus, 6.7% hepatitis B virus + hepatitis C virus, 11.7% alcoholic and 8.3% cryptogenic). Fifty-three percent of the HCC patients died within a median of 7.5 months. The mean serum level of IL-29 in patients with HCC was higher than that in the control group (32.55 pg/ml vs 11.46 pg/ml, p 0.05). The biomarkers were divided into two groups according to their median level. In the log rank analysis, biomarkers had no effect on survival (p > 0.05). Conclusions: IL-29 and galectin-3 levels were significantly higher in HCC patients. Although IL-29 and galectin-3 can be used as diagnostic markers for HCC, they had no prognostic value in HCC patients

    Anti-neuronal and stress-induced-phosphoprotein 1 antibodies in neuro-Behçet's disease

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    No disease-specific neuronal antibodies have so far been defined in neuro-Behçet's disease (NBD). Immunohistochemistry and immunocytochemistry studies showed antibodies to hippocampal and cerebellar molecular layers and the surface antigens of cultured hippocampal neurons in sera and/or cerebrospinal fluids (CSF) of 13 of 20 NBD and 6 of 20 BD patients but not in multiple sclerosis or headache controls. Screening with a protein macroarray led to identification of stress-induced-phosphoprotein-1 (STIP-1) as an antigenic target. High-titer STIP-1-antibodies were detected in 6 NBD patients' sera but not in controls. These results suggest that neuronal antibodies could be useful as diagnostic biomarkers in NBD. © 2011 Elsevier B.V

    Progressive encephalomyelitis with rigidity and myoclonus: a syndrome with diverse clinical features and antibody responses.

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    BACKGROUND/AIMS: To better characterize progressive encephalomyelitis with rigidity and myoclonus (PERM) syndrome and identify novel PERM phenotypes. METHODS: The clinical features and antibody status of PERM patients were investigated using immunoblots, cell-based assays, RIA, protein macroarray and ELISA. RESULTS: Two patients with supratentorial involvement showed abnormal PET or EEG findings. One patient was discovered to have renal cell carcinoma, and protein macroarray revealed Ma3-antibodies. Another patient with leucine-rich, glioma-inactivated 1 (LGI1) and glutamic acid decarboxylase (GAD) antibodies showed a good response to immunotherapy. CONCLUSION: The heterogeneity of the immunological features suggests that PERM is caused by diverse pathogenic mechanisms. Seropositivity to well-characterized neuronal cell surface antigens might indicate a good treatment response

    An analysis of antibody response following the second dose of CoronaVac and humoral response after booster dose with BNT162b2 or CoronaVac among healthcare workers in Turkey

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    Limited data are available on the short- to midterm levels of antibodies to the CoronaVac vaccine and quantitative change in humoral response after homologous or heterologous booster doses. In this prospective cohort study, we evaluated the anti-receptor-binding domain (RBD) immunoglobulin G (IgG) levels after two doses of CoronaVac and heterologous/homologous booster administration among healthcare workers in a university hospital in Turkey. Quantitative anti-RBD IgG antibody levels were measured at first and fourth months in 560 healthcare workers who had completed two doses of CoronaVac vaccine, and within 2 months after the third dose of CoronaVac or BNT162b2. Participants were asked to complete a questionnaire during the first blood draw. The seropositivity rate was 98.9% and 89.1%, and the median antibody level was 469.2 AU/ml and 166.5 AU/ml at first and fourth month, respectively. In the fourth month, a mean reduction of 61.4% +/- 20% in antibody levels was observed in 79.8% of the participants. The presence of chronic disease (odds ratio [OR]: 1.76, 95% confidence interval [CI]: 1.15-2.69) and being in the 36-50 age group (OR: 2.11, 95% CI: 1.39-3.19) were identified as independent predictors for low antibody response. The antibody level increased 104.8-fold (median: 17 609.4 vs. 168 AU/ml) and 8.7-fold (median: 1237.9 vs. 141.4 AU/ml) in the participants who received BNT162b2 and CoronaVac, respectively. During the follow-up, 25 healthcare workers (4.5%) were infected with severe acute respiratory syndrome coronavirus 2. Considering the waning immunity and circulating variants, a single booster dose of messenger RNA vaccine seems reasonable after the inactivated vaccine especially in risk groups
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