552 research outputs found

    Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet

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    [EN] In the present work, we experimentally investigated the effect of initial liquid droplet size on the evaporation in the heterogeneous droplet. Spherical carbon and water were used for particle and liquid droplet comprising the heterogeneous droplet. four initial droplet volumes of 1, 2, 3 and 4 μl were considered when the diameter of the particle was 5 mm. The heterogeneous droplet was suspended with a rod at 20 cm away from the radiator which surface temperature was fixed to 473 K. Ambient temperature and relative humidity remained 296 K and 40 %, respectively, during the experiment. As the results, the evaporation rate of 4 μl case increased about 1.8 times compared with that of 1 μl case. The evaporation rate increased almost linearly with the volume ratio, and that is related closely with the contact surface between particle and water droplet. Contact surface area remained almost constantly with time, whereas it increased with the initial volume of water droplet. The energy from radiator can be accumulated at the contact surface at the side of particle, thereby intensifying the evaporation of water droplet because more heat transfers from particle to droplet through the contact surface. Consequently, the initial volume of liquid droplet is one of the influence factors on the evaporation rate in the heterogenous droplet.This research was supported by the Fire Fighting Safety & 119 Rescue Technology Research and Development Program funded by the Ministry of Public Safety and Security (NEMA-NG-2014-46) and Research Project of Air Sampling Detector funded by Alllitelife co. Inc..Sung, KH.; Nam, JS.; Hong, GB.; Ryou, HS. (2017). Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 290-295. https://doi.org/10.4995/ILASS2017.2017.4744OCS29029

    Relationship of Vertigo and Postural Instability in Patients With Vestibular Schwannoma

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    Objectives Growth of vestibular schwannomas (VS) causes progressive vestibular symptoms and postural instability. Since the tumor grows slowly, compensation of decaying vestibular input may decrease subjective symptoms of dizziness. This study aims to estimate the relationship of subjective vestibular symptoms and objective postural instability in patients with VS. Methods A retrospective review of 18 patients newly diagnosed with VS and with subjective vertigo symptoms was performed. The results of vestibular function tests including the sensory organization test (SOT) using computerized dynamic posturography, caloric test, and self-report measures of subjective dizziness handicap (Dizziness Handicap Inventory) and visual analogue scale were compared according to the onset of vertigo symptoms. Results In VS patients, SOT showed decreased equilibrium score for all vestibular function related conditions, condition (C) 5 and 6, and composite (COMP) score. COMP scores were not correlated with visual analogue scale or Dizziness Handicap Inventory scores. Acute onset group included six patients and insidious onset group, 12 patients. Equilibrium scores for C5 and C6, and COMP scores were lower for insidious onset group, but the difference was not statistically significant. Conclusion Our findings confirmed postural instability is prevalent in VS patients. SOT parameters did not differ significantly between acute onset and insidious onset groups, but increased tumor size and canal weakness were noted in the insidious onset group. Clinicians should consider that postural instability is likely present even in patients who do not complain of acute vertigo, and appropriate counseling should be discussed with the patients

    The Differential Effects of Acute Right- vs. Left-Sided Vestibular Deafferentation on Spatial Cognition in Unilateral Labyrinthectomized Mice

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    This study aimed to investigate the disparity in locomotor and spatial memory deficits caused by left- or right-sided unilateral vestibular deafferentation (UVD) using a mouse model of unilateral labyrinthectomy (UL) and to examine the effects of galvanic vestibular stimulation (GVS) on the deficits over 14 days. Five experimental groups were established: the left-sided and right-sided UL (Lt.-UL and Rt.-UL) groups, left-sided and right-sided UL with bipolar GVS with the cathode on the lesion side (Lt.-GVS and Rt.-GVS) groups, and a control group with sham surgery. We assessed the locomotor and cognitive-behavioral functions using the open field (OF), Y maze, and Morris water maze (MWM) tests before (baseline) and 3, 7, and 14 days after surgical UL in each group. On postoperative day (POD) 3, locomotion and spatial working memory were more impaired in the Lt.-UL group compared with the Rt.-UL group (p < 0.01, Tamhane test). On POD 7, there was a substantial difference between the groups; the locomotion and spatial navigation of the Lt.-UL group recovered significantly more slowly compared with those of the Rt.-UL group. Although the differences in the short-term spatial cognition and motor coordination were resolved by POD 14, the long-term spatial navigation deficits assessed by the MWM were significantly worse in the Lt.-UL group compared with the Rt.-UL group. GVS intervention accelerated the vestibular compensation in both the Lt.-GVS and Rt.-GVS groups in terms of improvement of locomotion and spatial cognition. The current data imply that right- and left-sided UVD impair spatial cognition and locomotion differently and result in different compensatory patterns. Sequential bipolar GVS when the cathode (stimulating) was assigned to the lesion side accelerated recovery for UVD-induced spatial cognition, which may have implications for managing the patients with spatial cognitive impairment, especially that induced by unilateral peripheral vestibular damage on the dominant side

    Hyperbilirubinemia and Follow-up Auditory Brainstem Responses in Preterm Infants

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    Objectives. Neonatal hyperbilirubinemia is considered one of the most common causative factors of hearing loss. Preterm infants are more vulnerable to neuronal damage caused by hyperbilirubinemia. This study aimed to evaluate the effect of hyperbilirubinemia on hearing threshold and auditory pathway in preterm infants by serial auditory brainstem response (ABR). In addition, we evaluate the usefulness of the unconjugated bilirubin (UCB) level compared with total serum bilirubin (TSB) on bilirubin-induced hearing loss. Methods. This study was conducted on 70 preterm infants with hyperbilirubinemia who failed universal newborn hearing screening by automated ABR. The diagnostic ABR was performed within 3 months after birth. Follow-up ABR was conducted in patients with abnormal results (30 cases). TSB and UCB concentration were compared according to hearing threshold by ABR. Results. The initial and maximal measured UCB concentration for the preterm infants of diagnostic ABR ≥40 dB nHL group (n=30) were statistically higher compared with ABR ≤35 dB nHL group (n=40) (P=0.031 and P=0.003, respectively). In follow-up ABR examination, 13 of the ABR ≥40 dB nHL group showed complete recovery, but 17 had no change or worsened. There was no difference in bilirubin level between the recovery group and non-recovery group. Conclusion. UCB is a better predictor of bilirubin-induced hearing loss than TSB in preterm infants as evaluated by serial ABR. Serial ABR testing can be a useful, noninvasive methods to evaluate early reversible bilirubin-induced hearing loss in preterm infants

    Prognostic Factors Affecting Surgical Outcomes in Squamous Cell Carcinoma of External Auditory Canal

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    Objectives Carcinomas of the external auditory canal (EAC) are rare, and management remains challenging. Previous studies seeking prognostic factors for EAC cancers included cancers other than carcinomas. In this study, we analyzed the treatment outcomes of, prognostic factors for, and survival rates associated with specifically squamous cell carcinoma (SCC) of the EAC. Methods A retrospective review of 26 consecutive patients diagnosed with SCCs of the EAC in a 10-year period was performed in terms of clinical presentation, stage, choice of surgical procedure, and adjunct therapy. Overall survival (OS) and recurrence-free survival (RFS) were calculated and univariate analysis of prognostic factors was performed. Results The median age of the 26 patients with SCCs of the EAC was 63 years (range, 40 to 72 years), and 16 males and 10 females were included. According to the modified University of Pittsburgh staging system, the T stages were T1 in 11, T2 in six, T3 in four, and T4 in five cases. The surgical procedures employed were wide excision in three cases, lateral temporal bone resection (LTBR) in 17, and extended LTBR in four, and subtotal temporal bone resection in two. Two patients underwent neoadjuvant chemotherapy, and two underwent adjuvant chemotherapy. One patient received preoperative radiation therapy, and eleven received postoperative radiation therapy. Of the possibly prognostic factors examined, advanced preoperative T stage and advanced overall stage were significant predictors of RFS, but not of OS. Conclusion The advanced T stage and overall stage were associated with decreased survival after surgical treatment in patients with SCC of the EAC, highlighting the importance of clinical vigilance and early detection

    B Cell Immunophenotyping and Transcriptional Profiles of Memory B Cells in Patients with Myasthenia Gravis

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    Myasthenia gravis (MG) is an autoimmune neuromuscular junction disorders mediated by various autoantibodies. Although most patients with MG require chronic immunosuppressive treatment to control disease activity, appropriate surveillance biomarkers that monitor disease activity or potential toxicity of immunosuppressants are yet to be developed. Herein, we investigated quantitative distribution of peripheral blood B cell subsets and transcriptional profiles of memory B cells (CD19+ CD27+) in several subgroups of MG patients classified according to the Myasthenia Gravis Foundation of America (MGFA) Clinical Classification. This study suggests potential immunologic B-cell markers that may guide treatment decision in future clinical settings.N

    Chylous Leakage: A Rare Complication after Axillary Lymph Node Dissection in Breast Cancer and Surgical Management

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    Chylous leakage is an extremely rare complication of surgery for breast cancer. We experienced a case of chylous leakage after axillary lymph node dissection. A 38-year-old woman with invasive ductal carcinoma in the left breast underwent a modified radical mastectomy after four cycles of neoadjuvant chemotherapy. The postoperative serosanguinous drainage fluid became "milky" on the fourth postoperative day. After trying conservative management, we re-explored the axilla and ligated the lymphatic trunk. Although the success of many cases supports conservative management, timely surgical intervention represents an alternative in cases where leakage persists or where the output is high
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