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Abstract: In this study the efficiency of polycrystalline silicon solar cells was increased carving micro channel structures using a laser. In research to date, micro channel structures on the surface of polycrystalline silicon solar cells have been manufactured and studied. In an experiment polycrystalline silicon solar cell with micro channel structures on the surface demonstrated an increase in efficiency of 0.23–1.50%, as the radius of the micro channel structures varied from 15μm to 35μm. Micro channels also improved the Fill Factor of polycrystalline silicon solar cells. However, the efficiency started to decrease when the radius of the micro channel structures was greater than 40μm. Detailed features of the variation in current voltage of polycrystalline silicon solar cells with micro channels are discussed. [Copyright &y& Elsevier]

Abstract: Unlike neural stem cells that maintain populations in the adult brains of both rodents and humans, cochlear stem cells appear to diminish in number after birth and may become quiescent in adult mammalian cochleae. Hypoxia has been observed to promote an undifferentiated cell state in various stem cell populations; however, little is known about such an effect on cochlear stem/progenitor cells (SPCs). The aims of this study were to assess the effect of hypoxia on cochlear SPCs and to examine the impact of hypoxia-inducible factor-1alpha (Hif-1a) on regulating such an effect. Our data demonstrate that hypoxic culturing for 24 h significantly increased sphere formation and viability of cochlear SPCs compared with those cultured under normoxic conditions. Concurrent with these proliferation promotion effects are changes in the expression of multiple stemness and cell-cycle quiescent associated gene targets, including Abcg2, nestin, p27Kip1 and Vegf. Knockdown of Hif-1a expression by small-interfering RNA inhibited hypoxia-induced cochlear SPC expansion and resulted in downregulation of Vegf, Abcg2, and nestin and upregulation of p27Kip1 gene expression. These results suggest that Hif-1a plays an important role in the stimulation of the proliferation of cochlear SPCs, which confers a great benefit of expanding cochlear SPCs via hypoxic conditions. [Copyright &y& Elsevier]

Objectives: Recurrent idiopathic sudden sensorineural hearing loss (ISSNHL) is a rare disease. In this study, we evaluated the correlations between hearing recovery after the first and recurrent episodes of ISSNHL and characterized the clinical features of different episodes of ISSNHL.Methods: This retrospective study was conducted by reviewing medical records pertaining to the period 2008-2018. A total of 30 patients (16 male, 14 female) who had experienced at least two episodes of ISSNHL were included. All patients were had received steroid therapy (including systemic and IT) and/or hyperbaric oxygen therapy within 2 weeks after the onset of disease. The SDRG's criteria was used for the grading of hearing recovery.Results: The median age at the first and second episode of ISSNHL was 48 and 53.5 years, respectively; a total of 30% of patients presented with vertigo in the first episode and 40% presented with vertigo in the second episode. The hearing outcomes of both episodes showed significant improvement after treatment. The rate of complete recovery after the first and second episodes was 46.67% and 33.33%, respectively. A significant positive correlation was observed between the treatment outcomes of the first and second episodes (r = 0.721, p < 0.001).Conclusion: In ISSNHL, hearing recovery after a recurrent episode is significantly correlated with the hearing outcome after the initial episode (p = 0.042). The treatment outcome of the first episode is a prognostic factor for the outcomes of recurrent episodes. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Previously, our group reported that sphere-forming cells derived from the organ of Corti represent the stem/progenitor cells (SPCs) of the cochlea due to their properties of self-renewal and multipotency. However, long-term propagation of sphere-forming cells under suspension culture conditions may fail to maintain the characteristic stemness of these cells. Therefore, this study investigated whether an adherent culture system would be beneficial in terms of preserving more stem-like cells for long-term manipulations in vitro. Methods: Isolated modiolus-derived SPCs were placed on poly-d-lysine-coated petri dishes to form the so-called “adherent” culture system. Results: Modiolus SPCs cultured under adherent conditions exhibited a significantly increased percentage of cells with the side population (SP) phenotype (18.6%) compared with cells cultured under conventional suspension culture conditions (0.8%). Even after repeated passages, modiolus SPCs cultured under adherent culture conditions preserved more SP phenotype cells. In comparison with the non-SP phenotype cells, the sorted SP cells exhibited more stem-like but less differentiated properties, with an upregulated expression of the ATP-binding cassette subfamily G member 2 (ABCG2), Nestin, Sox2, and Nanog proteins. Furthermore, Retinoic acid (RA) treatment confirmed the expression of the multipotent differentiation markers in the SP cells, including TUJ1, pancytokeratin, glial fibrillary acidic protein (GFAP), and p27Kip1. Conclusion: Employment of an adherent culture system, instead of a suspension culture system, resulted in the enrichment of the SP cells from SPCs while retaining their stemness and multipotency. [Copyright &y& Elsevier]

Background: Ansa cervicalis (AC)–recurrent laryngeal nerve anastomosis (RLN) is usually not desirable for correction of paralytic dysphonia when it is difficult to find a viable distal stump of the recurrent laryngeal nerve. Nerve implantation of the thyroarytenoid muscle with the ansa cervicalis is a simple alternative method. Study design: Ten patients with unilateral vocal cord paralysis were prospectively designed to receive nerve implantation. A minimum period of 12 months after onset of paralysis was allowed to elapse to permit possible spontaneous reinnervation or compensation. Patients were followed long enough (at least 2 years) to determine if the procedure was successful. All patients were subjected to preoperative and postoperative voice recording, acoustic analysis, and videolaryngoscopy. Some of them underwent laryngeal electromyography. Results: Ten patients underwent nerve implantation of the thyroarytenoid muscles by using the ansa cervicalis, and 8 of 10 (80%) had improved phonatory quality. Laryngeal electromyography showed that the procedure produced satisfactory reinnervation of the thyroarytenoid muscle. Conclusions: Nerve implantation of the thyroarytenoid muscle by the anso cervicalis is a simple and efficient alternative to nerve transfer if dense scarring at the cricothyroid articulation and lack of a viable distal stump of the recurrent laryngeal nerve preclude the procedure of nerve transfer. But careful selection of the appropriate candidate seems to be the earliest prerequisite for a successful procedure. [Copyright &y& Elsevier]

Objectives: Posterior benign paroxysmal positional vertigo (p-BPPV) is the most common type of BPPV, and canalith-repositioning procedure (CRP) is frequently applied for treatment. Supine to prolonged lateral position (SPLP), a simple home-based maneuver, can be performed for treatment of p-BPPV. The purpose of this study was to investigate whether combination of CRP and SPLP could be more effective in symptom alleviation compared with CRP alone and reduce times of repeated CRP for patients with p-BBPV.Methods: A retrospective chart review enrolled 96 patients diagnosed with primary p-BPPV. Of these patients, 64 patients were included in the CRP group and 32 patients, in the CRP+SPLP group. The outcome was determined according to days required to reach negative result in Dix-Hallpike test, duration of vertigo and dizziness following the first repositioning procedure, and times of CRP performed to reach resolution of p-BPPV.Results: Of patients in the CRP and CRP+SPLP groups, 38% and 16% received CRP at least twice to reach resolution, respectively (P = 0.034). Patients in the CRP group and CRP+SPLP group spent an average of 9.8 ± 6.1 days and 7.9 ± 3.4 days, respectively reaching a negative result in Dix-Hallpike test (P = 0.050). In terms of duration for relieving vertigo and dizziness, the CRP+SPLP group achieved symptom relief with shorter duration (P = 0.036 and P = 0.025, respectively).Conclusion: Compared with CRP alone, combination of CRP and SPLP improved the therapeutic effectiveness and shortened the duration of suffering from vertigo and dizziness in patients with p-BPPV. [ABSTRACT FROM AUTHOR]

Objective: To investigate the latency and amplitude of auditory brainstem response (ABR) and hearing prognosis in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).Methods: Patients with ISSNHL were classified into four different recovery groups. All patients' clinical and demographic features were analyzed. Two-channel ABRs were collected in response to click stimuli at 90dB nHL. ABR amplitudes for wave I and ABR latency for waves I, III, and V were analyzed.Results: One hundred and two patients (54 men and 48 women) were included in the study. Hearing recovery was observed in 72 cases (70.6%). Waves I, III, and V latencies were significantly prolonged in the affected ears compared with the unaffected ears. A smaller wave I amplitude was found in the affected ear compared with the unaffected ear in the three recovery groups. There was a significant association between wave I latency and hearing outcome (p=0.009) with a prolonged trend from complete to slight hearing recovery group.Conclusions: There was a significant correlation between wave I latency and hearing outcome in patients with ISSNHL. The finding may provide diagnostic information and serve as a potential prognostic indicator in patients with ISSNHL. [ABSTRACT FROM AUTHOR]