Ferromagnetism and giant magnetoresistance in the rare earth fullerides Eu6-xSrxC60

We have studied crystal structure, magnetism and electric transport properties of a europium fulleride Eu6C60 and its Sr-substituted compounds, Eu6-xSrxC60. They have a bcc structure, which is an isostructure of other M6C60 (M represents an alkali atom or an alkaline earth atom). Magnetic measurements revealed that magnetic moment is ascribed to the divalent europium atom with S = 7/2 spin, and a ferromagnetic transition was observed at TC = 10 - 14 K. In Eu6C60, we also confirm the ferromagnetic transition by heat capacity measurement. The striking feature in Eu6-xSrxC60} is very large negative magnetoresistance at low temperature; the resistivity ratio \rho(H = 9 T)/\rho(H = 0 T) reaches almost 10^{-3} at 1 K in Eu6C60. Such large magnetoresistance is the manifestation of a strong pi-f interaction between conduction carriers on C60 and 4f electrons of Eu.Comment: 5 pages, 4 figure

The effect of resveratrol on the histologic characteristics of the cochlea in diabetic rats

PubMedID: 30284252Objectives/Hypothesis: The aim of this study was to investigate changes in the cochlea and the potential dose-dependent effects of resveratrol (RSV) against diabetes mellitus (DM) ototoxicity. Study Design: Animal model. Methods: Twenty-four male Wistar albino rats were divided into four groups. Baseline distortion product otoacoustic emission (DPOAE) measurements were evaluated. Group I was the control group, group II was made diabetic with single-dose streptozotocin, and groups III and IV were rendered diabetic as group II and administered 10 and 20 mg RSV, respectively, intraperitoneally for 4 weeks. All animals were sacrificed after repeated DPOAE measurement. Apoptosis was investigated using caspase-3, Bax (Bcl-associated X protein), and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining. Results: The DPOAE values in the diabetic group were found to be significantly lower compared with the other groups at 5,714 Hz and 8,000 Hz (P .05). The histopathologic investigation using caspase-3, Bax, and TUNEL staining showed that the mean rank of the diabetic group was significantly higher compared with the RSV10, RSV20, and control groups (DM > RSV10 > RSV20 > control) (P <.05). Conclusions: These results imply that RSV administration offered statistically significant protection for the cochleas of rats against diabetes. This protective effect improved histologically with higher doses. Level of Evidence: NA Laryngoscope, 129:E1–E6, 2019. © 2018 The American Laryngological, Rhinological and Otological Society, Inc

The Effect of Electronic Cigarettes on Voice Quality

PubMedID: 29884511Objectives: Cigarette-associated diseases have frequently been detected in the field of otolaryngology. Cigarettes can cause changes in voice performance. The aim of the present study was to investigate the effect of e-cigarettes on voice performance compared with conventional cigarettes. Materials and Methods: This is a cross-sectional study that included 81 healthy volunteers. To provide standardization, all patients were men. The patients were divided into three groups: e-cigarette users (group 1, n = 21), conventional cigarette users (group 2, n = 30), and nonsmokers who had never smoked (group 3, n = 30). The subjective and objective voice analyses were performed for all the three groups in the study. F0, jitter %, shimmer %, shimmer dB, harmonics-to-noise ratio (HNR) values, and Voice Handicap Index 10 were statistically compared between all groups. Results: The mean Voice Handicap Index 10 values of the conventional cigarette users were higher than those of the e-cigarette users and control group. No significant difference regarding the F0, jitter, and shimmer percentage values between the groups was detected; however, a significant difference was detected regarding the shimmer dB and HNR values between the groups. The mean shimmer dB values of the conventional cigarette group were higher than those of the control group and electronic cigarette users, but the mean HNR values were lower than those of the control group and electronic cigarette users. Conclusions: The effects of e-cigarettes on voice were detected as mild compared with conventional cigarettes, according to the subjective and objective voice analysis results in our study. © 2018 The Voice Foundatio

The effect of very low dose pulsed magnetic waves on cochlea [Efeito de ondas magnéticas pulsadas de dosagem extremamente baixa na cóclea]

PubMedID: 30583943Introduction: In daily life biological systems are usually exposed to magnetic field forces at different intensities and frequencies, either directly or indirectly. Despite negative results, the therapeutic use of the low dose magnetic field has been found in recent studies. The effect of magnetic field forces on cochlear cells is not clear in the literature. Objective: In our study, we first applied in vivo pulsed magnetic fields to laboratory rats to investigate the effects on cochlea with distortion product otoacoustic emission test followed by histopathological examinations. Methods: Twelve rats were included in this study, separated into two groups as study group and control group. The rats in the study group were exposed to 40 Hz pulsed magnetic field for 1 h/day for 30 days; the hearing of the rats was controlled by otoacoustic emission test. Also, their cochleas were removed and histochemical examination was performed by Caspase-3, Caspase-9, and TUNEL methods. Results: A statistically significant difference was determined (p < 0.05) when the hearing thresholds of the groups obtained by using 5714 Hz and 8000 Hz stimuli were compared by Kruskal–Wallis test. A significant reaction was observed in the study group, especially in the outer ciliated cells during immunohistochemical examinations by using Caspase-3 and Caspase-9 methods. A significantly positive difference was determined in the study group, especially at the outer ciliated cells and the support cells of the corti organ, when compared to the control group (p < 0.05) by the TUNEL method. Conclusion: According to the results of our study, the very low dose magnetic field, which is considered to be used for therapeutic purposes recently, can cause both auditory function defects and histopathologic damage in cochlear cells. © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facia

The effect of resveratrol on the histologic characteristics of the cochlea in diabetic rats

Objectives/Hypothesis: The aim of this study was to investigate changes in the cochlea and the potential dose-dependent effects of resveratrol (RSV) against diabetes mellitus (DM) ototoxicity. Study Design: Animal model. Methods: Twenty-four male Wistar albino rats were divided into four groups. Baseline distortion product otoacoustic emission (DPOAE) measurements were evaluated. Group I was the control group, group II was made diabetic with single-dose streptozotocin, and groups III and IV were rendered diabetic as group II and administered 10 and 20 mg RSV, respectively, intraperitoneally for 4 weeks. All animals were sacrificed after repeated DPOAE measurement. Apoptosis was investigated using caspase-3, Bax (Bcl-associated X protein), and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining. Results: The DPOAE values in the diabetic group were found to be significantly lower compared with the other groups at 5,714 Hz and 8,000 Hz (P .05). The histopathologic investigation using caspase-3, Bax, and TUNEL staining showed that the mean rank of the diabetic group was significantly higher compared with the RSV10, RSV20, and control groups (DM > RSV10 > RSV20 > control) (P <.05). Conclusions: These results imply that RSV administration offered statistically significant protection for the cochleas of rats against diabetes. This protective effect improved histologically with higher doses. Level of Evidence: NA Laryngoscope, 129:E1–E6, 2019. © 2018 The American Laryngological, Rhinological and Otological Society, Inc

Effects of Cysteamine on Sheep Embryo Cleavage Rates

Oxidative stress during in vitro culture leads to defects in development of gametes and embryos. Several antioxidants such as cysteamine, L-ascorbic acid, beta mercaptoethanol, cysteine, glutathione, proteins, vitamins have been used to supplement culture media to counter the oxidative stress. This study was conducted to detect the effect of adding cysteamine to the maturation medium to subsequent cleavage rates of sheep embryos. Totally 604 ovaries were obtained by ten replica and 2060 oocytes were collected. The cumulus oocyte complexes were recovered by the slicing method. A total of 1818 selected oocytes were divided into two groups and used for maturation (88.25%). The first group was created as supplemented with cysteamine (Group A) and second group (Group B, control) without cysteamine in TCM-199. The two groups were incubated for 24 h at 38.8 °C in an atmosphere of 5% CO2 in humidified air for in vitro maturation (IVM). After IVM, oocytes were fertilized with 50 x 107 / mL fresh ram semen in BSOF medium for 18 h. After fertilization, maturation groups were divided into two subgroups with different culture media: Group AI-SOF (Synthetic Oviduct Fluid medium), Group AII-CR1aa (Charles Rosencrans medium), Group BI-SOF and Group BII-CR1aa were achieved. Cleavage rates were evaluated at day 2. post insemination. The rates of cleavage were detected as 59.54% (184/309), 55.44% (173/312), 65.34% (215/329), 59.34% (200/337) respectively, with showing no statistically significant difference between the groups at the level of P>0.05. In conclusion, supplementing cysteamine to maturation media in TCM-199 did not affect the cleavage rates of sheep embryos in SOF and CR1aa culture media