Polarization retention of thin ferroelectric poly(vinylidene fluoride-co-trifluoroethylene film capacitors

Excellent retention of the initial remanent polarizations was observed in ca. 200 nm thick ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) film capacitors with the writing pulse amplitude and time width of +/- 20 V and 1 ms, respectively, over 200 h at 80 degrees C. The opposite state program turned out more sensitive to retention deterioration than the same state one in both switching and nonswitching mode when either writing pulse amplitude or time width decreases. Nonswitching retention in the opposite state mode is in particular one of the most critical properties for designing a ferroelectric polymer capacitor memoryopen8

Decision tree-based approach for online management of PEM fuel cells for residential application

This thesis demonstrates a new intelligent technique for the online optimal management of PEM fuel cells units for onsite energy production to supply residential utilizations. Classical optimization techniques are based on offline calculations and cannot provide the necessary computational speed for online performance. In this research, a Decision Tree (DT) algorithm is employed to obtain the optimal, or quasioptimal, settings of the fuel cell online and in a general framework. The main idea is to employ a classification technique, trained on a sufficient subset of data, to produce an estimate of the optimal setting without repeating the optimization process. A database is extracted from a previously-performed Genetic Algorithm (GA)-based optimization has been used to create a suitable decision tree, which was intended for generalizing the optimization results. The approach provides the flexibility of adjusting the settings of the fuel cell online according to the observed variations in the tariffs and load demands. Results at different operating conditions are presented to confirm the high accuracy of the proposed generalization technique. The accuracy of the decision tree has been tested by evaluating the relative error with respect to the optimized values. Then, the possibility of pruning the tree has been investigated in order to simplify its structure without affecting the accuracy of the results. In addition, the accuracy of the DTs to approximate the optimal performance of the fuel cell is compared to that of the Artificial Neural Networks (ANNs) used for the same purpose. The results show that the DTs can somewhat outperform the ANNs with certain pruning levels

Exploring the Association between Thyroid Function and Frailty: Insights from Representative Korean Data

Background This study investigates the association between thyroid function and frailty in the old patients using representative data. Methods The study was conducted using data from the Korea National Health and Nutrition Examination Survey conducted from 2013 to 2015. The study population included 2,416 participants aged 50 years and older with available thyroid function test data. Frailty assessment was performed using the Fried frailty phenotype. The prevalence of frailty was analyzed across different thyroid diseases and thyroid function parameters. Results The significant association between thyroid dysfunction and frailty was observed in overt hyperthyroidism and subclinical hyperthyroidism. After adjusting for various factors, the association between thyroid dysfunction and frailty remained significant. On the other hand, overt hypothyroidism did not show a significant association with frailty in the adjusted analysis. For individuals with overt hyperthyroidism and subclinical hyperthyroidism, higher levels of free thyroxine (FT4) were significantly associated with an increased risk of frailty (aOR >999; 95% CI, >999 to 999). Among individuals with overt hypothyroidism, lower level of FT4 levels and high thyrotropin (TSH) levels showed a significant association with frailty risk (FT4: aOR, <0.01; TSH: aOR, 999). In participants with subclinical hypothyroidism, there were no significant associations between parameters for thyroid and frailty risk. Conclusion These findings suggest that thyroid dysfunction, particularly overt hyperthyroidism and subclinical hyperthyroidism, may be associated with an increased risk of frailty in the old patients

Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

A 57-year-old woman experienced bilateral acute ischemic optic neuropathy after spine surgery. Routine MR imaging sequence, T2-weighted image, showed subtle high signal intensity on bilateral optic nerves. A contrast-enhanced T1 weighted image showed enhancement along the bilateral optic nerve sheath. Moreover, diffusion-weighted image (DWI) and an apparent diffusion coefficient map showed markedly restricted diffusion on bilateral optic nerves. Although MR findings of T2-weighted and contrast enhanced T1-weighted images may be nonspecific, the DWI finding of cytotoxic edema of bilateral optic nerves will be helpful for the diagnosis of acute ischemic optic neuropathy after spine surgery

Robot-assisted posterior retroperitoneoscopic adrenalectomy: single port access

Laparoscopic adrenalectomy has become a gold standard in adrenal gland surgery. More recently, some minimally invasive trials have been conducted on single access surgery on the adrenal gland. In this study, we introduce our first experiences of robot-assisted posterior retroperitoneoscopic adrenalectomy using single-port access and the da Vinci system

Prefoldin 5 and Anti-prefoldin 5 Antibodies as Biomarkers for Uveitis in Ankylosing Spondylitis

Objective: Uveitis is the most common extra-articular manifestation of ankylosing spondylitis (AS), for which no diagnostic biomarkers have been identified. This study was conducted to identify biomarker for uveitis in AS.Methods: To identify autoantibodies associated with uveitis in AS, we performed human protein microarray analysis using sera derived from various autoimmune diseases and ELISA analysis of sera derived from AS and rheumatoid arthritis patients. In the curdlan-induced SKG mice model, ophthalmic examination was performed at week 8 post-immunization and histologic examination of the ocular lesions performed at week 16 post-immunization. Serum levels of target antibodies were assessed at various time-points. To evaluate the functional role of specific autoantibodies, an in vitro apoptosis assay using ARPE-19 cells was performed.Results: Reactivity against prefoldin subunit 5 (PFDN5) was identified in AS with uveitis. Levels of anti-PFDN5 antibodies and PFDN5 in sera from AS with uveitis patients were significantly higher than those in AS without uveitis. At week 8, half of curdlan-treated SKG mice developed anterior uveitis, while all of them developed histologically confirmed uveitis at week 16. The levels of anti-PFDN5 antibodies increased over time in the sera of curdlan-treated SKG mice along with increased expression of PFDN5 and apoptosis in the ocular lesions. Knockdown of PFDN5 in ARPE19 cells resulted in increased apoptosis, suggesting a protective role of PFDN5 against cell death in uveitis.Conclusion: AS patients with uveitis have increased levels of anti-PFDN5 antibodies, and our findings suggest that anti-PFDN5 antibodies could provide a biomarker for uveitis in AS