Positioning the ETT by auscultation places the ETT more deeply than the midtrachea, which can increase the risk of endobronchial intubation during neck flexion.

Hypoxia-mediated neurotoxicity contributes to various neurodegenerative disorders, including Alzheimer disease. Neuregulin-1 (NRG1) plays an important role in the development and plasticity of the brain. The aim of the present study was to investigate the neuroprotective effect and the regulating hypoxic inducible factor of NRG1 in cobalt chloride (CoCl2) induced hypoxia. Methods: Hypoxia was induced in SH-SY5Y cells by CoCl2 treatment. SH-SY5Y cells were pretreated with NRG1 and then treated with CoCl2. Western blotting, immunocytochemistry, and lactate dehydrogenase (LDH) release assays were performed to examine neuroprotective properties of NRG1 in SH-SY5Y cells. Results: Our data showed that CoCl2 induced cytotoxicity and changes of hypoxia-inducible factor-1α (HIF-1α) and p53 expression in SH-SY5Y cells. However, pretreatment with NRG1 inhibited CoCl2-induced accumulation of HIF-1α and p53 stability. In addition, NRG1 significantly attenuated cell death of SH-SY5Y induced by CoCl2. Conclusions: NRG1 can regulate HIF-1α and p53 to protect neurons against hypoxic damage.

Tinnitus patients suffer from not only auditory sensations but also physical, mental, and social difficulties. Even though tinnitus is believed to be associated with the autonomic nervous system, changes in autonomic conditions in tinnitus patients are not receiving much research attention. The aims of this study were to investigate the autonomic condition of tinnitus patients and to consider Korean medicine in the treatment of tinnitus with an evidence-based approach. We performed a retrospective chart review and compared the heart rate variability (HRV) parameters of 40 tinnitus patients (19 acute and 21 chronic) and 40 healthy controls. In tinnitus patients, the power of the high frequency component and total power of the HRV significantly decreased (P < 0.05), and the low frequency to high frequency ratio significantly increased (P < 0.05). There was no significant difference between the acute and chronic patients. When comparing each group with the controls, there was a tendency that the longer the duration of tinnitus was, the larger the observed HRV change was. In conclusion, tinnitus patients have vagal withdrawal and sympathetic overactivity, and chronic tinnitus more strongly affects autonomic conditions than acute tinnitus. This study provides evidence for Korean medical treatments of tinnitus, such as acupuncture and Qi-training, that cause modulation of cardiac autonomic function.

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Local and average mass transfer rates from a rectangular cylinder having various width to height ratios are measured using naphthalene sublimation technique, and influence of flow characteristics on mass transfer is investigated. The experimental apparatus comprises a wind tunnel, a naphthalene casting facility and a sublimation depth measurement system. Mass transfer data are compared with those of heat transfer which are obtained using thermocouples in the constant heat flux boundary condition, and analogy between heat and mass transfer is examined. The reasons for discrepancy in both transport values are explained in detail.