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41.
Mehmet Esref Alkis Hakki Murat Bilgin Veysi Akpolat Korkut Yegin Mehmet Cihan Yavas 《Electromagnetic biology and medicine》2019,38(1):32-47
Ubiquitous and ever increasing use of mobile phones led to the growing concern about the effects of radiofrequency radiation (RFR) emitted by cell phones on biological systems. The aim of this study is to explore whether long-term RFR exposure at different frequencies affects DNA damage and oxidant-antioxidant parameters in the blood and brain tissue of rats. 28 male Sprague Dawley rats were randomly divided into four equal groups (n = 7). They were identified as Group 1: sham-control, Group 2: 900 MHz, Group 3: 1800 MHz, and Group 4: 2100 MHz. Experimental groups of rats were exposed to RFR 2 h/day for 6 months. The sham-control group of rats was subjected to the same experimental condition but generator was turned off. Specific absorption rates (SARs) at brain with 1 g average were calculated as 0.0845 W/kg, 0.04563 W/kg, and 0.03957, at 900 MHz, 1800 MHz, and 2100 MHz, respectively. Additionally, malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), total antioxidant status (TAS), and total oxidant status (TOS) analyses were conducted in the brain tissue samples. Results of the study showed that DNA damage and oxidative stress indicators were found higher in the RFR exposure groups than in the sham-control group. In conclusion, 900-, 1800-, and 2100-MHz RFR emitted from mobile phones may cause oxidative damage, induce increase in lipid peroxidation, and increase oxidative DNA damage formation in the frontal lobe of the rat brain tissues. Furthermore, 2100-MHz RFR may cause formation of DNA single-strand breaks. 相似文献
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Steven P. Govek Celine Bonnefous Jackaline D. Julien Johnny Y. Nagasawa Mehmet Kahraman Andiliy G. Lai Karensa L. Douglas Anna M. Aparicio Beatrice D. Darimont Katherine L. Grillot James D. Joseph Joshua A. Kaufman Kyoung-Jin Lee Nhin Lu Michael J. Moon Rene Y. Prudente John Sensintaffar Peter J. Rix Nicholas D. Smith 《Bioorganic & medicinal chemistry letters》2019,29(3):367-372
Potent estrogen receptor ligands typically contain a phenolic hydrogen-bond donor. The indazole of the selective estrogen receptor degrader (SERD) ARN-810 is believed to mimic this. Disclosed herein is the discovery of ARN-810 analogs which lack this hydrogen-bond donor. These SERDs induced tumor regression in a tamoxifen-resistant breast cancer xenograft, demonstrating that the indazole NH is not necessary for robust ER-modulation and anti-tumor activity. 相似文献
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Hacer Esen Saadet Alpdağtaş Mehmet Mervan Çakar 《Preparative biochemistry & biotechnology》2019,49(5):529-534
AbstractSeveral protein expression systems can be used to get enzymes in required quantities and study their functions. Incorporating a polyhistidine tag is a beneficial way of getting various enzymes such as FDHs for industrial applications. The NAD+ dependent formate dehydrogenase from Chaetomium thermophilum (CtFDH) can be utilized for interconversion of formate to carbon dioxide coupled with the conversion of NAD+ to NADH. In this study, N-terminal His tagged CtFDH (N-CtFDH) and C-terminal His tagged CtFDH (C-CtFDH) was constructed to learn the effect of His tag location on the activity and kinetic parameters of the enzyme. The solubility of proteins was not affected by tag position, however, an interference on the N-terminal region caused a deterioration in specific activity and the kinetic ability of enzyme. The obtained results indicated that the C-terminus of the enzyme is an appropriate region for tag engineering. The C-CtFDH has an approximately three-fold larger specific activity and two-fold higher catalytic efficiency than N-CtFDH. The results suggest that insertion of a His-tag at the N-terminal or C-terminal end of CtFDH has different effects on the protein and the N-terminal fragment of the protein is crucial for the function of CtFDH. 相似文献
45.
Cho CH Park J Nagrath D Tilles AW Berthiaume F Toner M Yarmush ML 《Biotechnology and bioengineering》2007,97(1):188-199
Bioartificial liver (BAL) devices have been developed to treat patients undergoing acute liver failure. One of the most important parameters to consider in designing these devices is the oxygen consumption rate of the seeded hepatocytes which are known to have oxygen consumption rates 10 times higher than most other cell types. Hepatocytes in various culture configurations have been tested in BAL devices including those formats that involve co-culture of hepatocytes with other cell types. In this study, we investigated, for the first time, oxygen uptake rates (OUR)s of hepatocytes co-cultured with 3T3-J2 fibroblasts at various hepatocyte to fibroblast seeding ratios. OURs were determined by measuring the rate of oxygen disappearance using a ruthenium-coated optical probe after closing and sealing the culture dish. Albumin and urea production rates were measured to assess hepatocyte function. Lower hepatocyte density co-cultures demonstrated significantly higher OURs (2 to 3.5-fold) and liver- specific functions (1.6-fold for albumin and 4.5-fold for urea production) on a per cell basis than those seeded at higher densities. Increases in OUR correlated well with increased liver-specific functions. OURs (V(m)) were modeled by fitting Michaelis-Menten kinetics and the model predictions closely correlated with the experimental data. This study provides useful information for predicting BAL design parameters that will avoid oxygen limitations, as well as maximize metabolic functions. 相似文献
46.
Thermal performance of quartz capillaries for vitrification 总被引:1,自引:1,他引:0
In this paper we report the thermal behavior of a new approach for vitrification. Thermal performance of traditional open pulled straws is compared with a new technique based on the combined use of quartz capillaries with slush nitrogen. This new method of vitrification achieved ultrafast cooling rates of 250,000 °C/min. As a result, a much lower concentration of cryoprotectant was needed to reach vitrification. In fact, a cryoprotectant solution typically used in oocyte slow freezing protocols was shown to remain transparent after cooling to liquid nitrogen temperatures indicating apparent “vitrification”. This approach offers a new and very promising technique for vitrification of cells using low levels of cryoprotectants. 相似文献
47.
Adaptive neuro-fuzzy modelling of anaerobic digestion of primary sedimentation sludge 总被引:1,自引:0,他引:1
Cakmakci M 《Bioprocess and biosystems engineering》2007,30(5):349-357
Modelling of anaerobic digestion systems is difficult because their performance is complex and varies significantly with influent
characteristics and operational conditions. In this study, Adaptive Neuro-Fuzzy Inference System (ANFIS) were used for modelling
of anaerobic digestion system of primary sludge of Kayseri municipal WasteWater Treatment Plant (WWTP). Effluent Volatile
Solid (VS) and methane yield were predicted by the ANFIS. Two stage models were performed. In the first stage, effluent VS
concentration was predicted using pH, VS concentration, flowrate of pre-thickened sludge and temperature of the influent as
input parameters. In the second stage, effluent VS concentration in addition to first stage input parameters were used as
input parameters to predict methane yield. The low Root Mean Square Error (RMSE) and high Index of agreement (IA) values were
obtained with subtractive clustering method of a first order Sugeno type inference. The model performance was evaluated with
statistical parameters. According to statistical evaluations, the models satisfactorily predict effluent VS concentration
and methane yield. 相似文献
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Caglayan Berrak Kilic Ertugrul Dalay Arman Altunay Serdar Tuzcu Mehmet Erten Fusun Orhan Cemal Gunal Mehmet Yalcin Yulug Burak Juturu Vijaya Sahin Kazim 《Molecular biology reports》2019,46(1):241-250
Molecular Biology Reports - Traumatic brain injury (TBI) is the leading cause of mortality and morbidity in young adults and children in the industrialized countries; however, there are presently... 相似文献
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