Freestanding flexible polymer films based on bridging of two EDOT units with functionalized chains for use in long-term-stable supercapacitors

2018 ◽  
Vol 42 (7) ◽  
pp. 4824-4834 ◽  
Author(s):  
Guo Ye ◽  
Qianjie Zhou ◽  
Danqin Li ◽  
Yinxiu Zuo ◽  
Xuemin Duan ◽  
...  
Keyword(s):  
Polymer Films ◽  
Cross Linking ◽  
Flexible Films ◽  
Flexible Polymer ◽  
Cycling Life

Freestanding flexible films were prepared by cross-linking two EDOT unit with fictionalized flexible chains, the application of these films in supercapacitors showed excellent cycling life.

Long term results of accelerated corneal collagen cross-linking in pediatric keratoconus

2021 ◽  
pp. 112067212110183
Author(s):  
Yasin Cinar ◽  
Cagla Cilem Han ◽  
Alparslan Sahin ◽  
Zeba A Syed
Keyword(s):  
Visual Acuity ◽  
Corneal Thickness ◽  
University Hospital ◽  
Long Term Results ◽  
Cross Linking ◽  
Distance Visual Acuity ◽  
The Mean ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Purpose: To evaluate the long term visual, refractive, and corneal tomographic outcomes of epithelium-off accelerated corneal collagen cross-linking (ACXL) in the management of pediatric keratoconus (KC). Methods: This retrospective study included patients under 18 years old with progressive KC who underwent ACXL between 2012 and 2019 at Dicle University Hospital. Complete ophthalmic examination was performed including uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (CDVA), manifest refraction, and corneal tomography. Evaluations were performed preoperatively and at 6 months intervals postoperatively. Results: Forty-nine eyes of 49 patients were included in the study. The mean age of patients at the time of ACXL was 14.2 ± 1.8 (range: 9.5–17.3) years. Mean follow up was 4.61 ± 1.90 (range: 2.0–8.1) years. The mean LogMAR UDVA improved from 0.94 ± 0.41 to 0.81 ± 0.43, 0.69 ± 0.41, and 0.67 ± 0.33 after 1, 3, and 5 years respectively ( p = 0.001). The mean LogMAR CDVA improved from 0.58 ± 0.36 to 0.46 ± 0.31, 0.34 ± 0.23, and 0.39 ± 0.27 after 1, 3, and 5 years respectively ( p = 0.015). The mean refractive cylinder improved significantly from 6.01 ± 2.07 diopters (D) to 5.46 ± 1.87, 5.38 ± 2.18, and 5.02 ± 2.31 D after 1, 3, and 5 years respectively ( p = 0.005). As compared to preoperative values, steep keratometry and maximum keratometry were not significantly different ( p = 0.805 and 0.448, respectively) following ACXL, while flat keratometry significantly improved after ACXL ( p = 0.012). Although central corneal thicknesses decreased significantly ( p = 0.029), the decrease in thinnest corneal thickness was not statistically significant ( p = 0.205). Conclusion: Epithelium-off ACXL seems to be effective for halting KC progression with long term clinical benefits in pediatric patients.

Functionality and chemical stability of plasma polymer films exhibiting a vertical cross-linking gradient in their subsurface

2018 ◽  
Vol 156 ◽  
pp. 259-268 ◽  
Author(s):  
Marianne Vandenbossche ◽  
Johanna Dorst ◽  
Martin Amberg ◽  
Urs Schütz ◽  
Patrick Rupper ◽  
...  
Keyword(s):  
Polymer Films ◽  
Chemical Stability ◽  
Plasma Polymer ◽  
Cross Linking

Impact of oral contraceptive use and menstrual phases on patellar tendon morphology, biochemical composition, and biomechanical properties in female athletes

2013 ◽  
Vol 114 (8) ◽  
pp. 998-1008 ◽  
Author(s):  
Mette Hansen ◽  
Christian Couppe ◽  
Christina S. E. Hansen ◽  
Dorthe Skovgaard ◽  
Vuokko Kovanen ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Female Athletes ◽  
Maximum Voluntary Contraction ◽  
Biomechanical Properties ◽  
Cross Sectional Area ◽  
Cross Linking ◽  
Sectional Area ◽  
Cross Sectional ◽  
Collagen Cross Linking

Sex differences exist with regards to ligament and tendon injuries. Lower collagen synthesis has been observed in exercising women vs. men, and in users of oral contraceptives (OC) vs. nonusers, but it is unknown if OC will influence tendon biomechanics of women undergoing regular training. Thirty female athletes (handball players, 18–30 yr) were recruited: 15 long-term users of OC (7.0 ± 0.6 yr) and 15 nonusers (>5 yr). Synchronized values of patellar tendon elongation (obtained by ultrasonography) and tendon force were sampled during ramped isometric knee extensor maximum voluntary contraction to estimate mechanical tendon properties. Furthermore, tendon cross-sectional area and length were measured from MRI images, and tendon biopsies were obtained for analysis of tendon fibril characteristics and collagen cross-linking. Overall, no difference in tendon biomechanical properties, tendon fibril characteristics, or collagen cross-linking was observed between the OC users and nonusers, or between the different phases of the menstrual cycle. In athletes, tendon cross-sectional area in the preferred jumping leg tended to be larger than that in the contralateral leg ( P = 0.09), and a greater absolute ( P = 0.01) and normalized tendon stiffness ( P = 0.02), as well as a lower strain ( P = 0.04), were observed in the jumping leg compared with the contralateral leg. The results indicate that long-term OC use or menstrual phases does not influence structure or mechanical properties of the patellar tendon in female team handball athletes.

scholarly journals Experimental Study of Advanced Helmholtz Resonator Liners with Increased Acoustic Performance by Utilising Material Damping Effects

2018 ◽  
Vol 8 (10) ◽  
pp. 1923
Author(s):  
Martin Dannemann ◽  
Michael Kucher ◽  
Eckart Kunze ◽  
Niels Modler ◽  
Karsten Knobloch ◽  
...  
Keyword(s):  
Polymer Films ◽  
Helmholtz Resonator ◽  
Broadband Noise ◽  
Acoustic Energy ◽  
Acoustic Damping ◽  
Acoustic Performance ◽  
Acoustic Liners ◽  
Flexible Polymer ◽  
Noise Absorption ◽  
Aero Engines

In aero engines, noise absorption is realised by acoustic liners, e.g., Helmholtz resonator (HR) liners, which often absorb sound only in a narrow frequency range. Due to developments of new engine generations, an improvement of overall acoustic damping performance and in particular more broadband noise absorption is required. In this paper, a new approach to increase the bandwidth of noise absorption for HR liners is presented. By replacing rigid cell walls in the liner’s honeycomb core structure by flexible polymer films, additional acoustic energy is dissipated. A manufacturing technology for square honeycomb cores with partially flexible walls is described. Samples with different flexible wall materials were fabricated and tested. The acoustic measurements show more broadband sound absorption compared to a reference liner with rigid walls due to acoustic-structural interaction. Manufacturing-related parameters are found to have a strong influence on the resulting vibration behaviour of the polymer films, and therefore on the acoustic performance. For future use, detailed investigations to ensure the liner segments compliance with technical, environmental, and life-cycle requirements are needed. However, the results of this study show the potential of this novel liner concept for noise reduction in future aero-engines.

scholarly journals Long-term Follow-up of Pachymetric and Topographic Alterations after Corneal Collagen Cross-Linking for Keratoconus

2012 ◽  
Vol 1 (1) ◽  
pp. 22-25
Author(s):  
Paraskevi G Zotta ◽  
Diamantis D Almaliotis ◽  
George D Kymionis ◽  
Vasilios F Diakonis ◽  
Kostas A Moschou ◽  
...  
Keyword(s):  
Corneal Thickness ◽  
Case Series ◽  
Cross Linking ◽  
Retrospective Case ◽  
Time Intervals ◽  
Long Term Follow Up ◽  
Collagen Cross Linking ◽  
Corneal Collagen

ABSTRACT Purpose To determine the long-term alterations of corneal thickness, along with topographic outcomes, after corneal collagen cross-linking treatment (CXL) for keratoconus. Materials and methods In this retrospective case series, 46 patients (52 eyes), 32 males and 14 females, with progressive keratoconus were included. All eyes underwent CXL in accordance with the standard protocol (Dresden) for the treatment of their ectatic corneal disorder between January 2006 and June 2007. Pachymetric and topographic outcomes were evaluated preoperatively and at 1, 3, 6, 12, 24 and 36 months postoperatively. Results Mean follow-up was 28.08 ± 8.39 months (range, from 12 to 36 months). A statistically significant decline in corneal pachymetric values (at the thinnest location) when compared with preoperative values (467.65 ± 41.08 µm) was demonstrated at 1 (437.63 ± 50.57 µm), 3 (439.08 ± 52.27 µm), 6 (449.37 ± 52.73 µm), 12 (449.63 ± 83.53 µm) and 24 (459.97 ± 47.32 µm) months after CXL (p < 0.05, for all mentioned time intervals). Return to preoperative pachymetric values (469.52 ± 40.52 µm) was revealed 36 months post-CXL (p > 0.05). With respect to topographic (flat and steep keratometric values, keratoconus index), no statistically significant differences between preoperative and all postoperative intervals were found (p > 0.05, for all values for all time intervals). Conclusion Corneal pachymetric values reduce significantly up to 24 months after CXL treatment, while a return to preoperative values was revealed 36 months after the procedure. No significant changes’ concerning topographic outcomes was demonstrated after CXL, indicating stability of these parameters. How to cite this article Zotta PG, Almaliotis DD, Kymionis GD, Diakonis VF, Moschou KA, Karampatakis VE. Long-term Follow-up of Pachymetric and Topographic Alterations after Corneal Collagen Cross-Linking for Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):22-25.

scholarly journals Corneal Cross-linking in Patients Younger than 18 Years: Long-term Follow-up in Three Israeli Medical Centers

2014 ◽  
Vol 3 (2) ◽  
pp. 84-87
Author(s):  
David Zadok ◽  
Isaac Avni ◽  
Erez Bakshi ◽  
Irina S Barequet ◽  
Isaac Aizenman ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Pediatric Population ◽  
Cross Linking ◽  
Safe Procedure ◽  
Medical Centers ◽  
Manifest Refraction ◽  
Uncorrected Visual Acuity ◽  
Long Term Follow Up

ABSTRACT Purpose To report refractive, topographic and safety outcomes of corneal cross-linking (CXL) in patients younger than 18 years of age with progressive keratoconus. Materials and methods In this retrospective study, we enrolled 31 eyes of 21 children aged 11 to 17 years that underwent corneal riboflavin-ultraviolet A induced CXL due to progressive keratoconus at three different ophthalmology departments in Israel. They were followed for 3 to 48 months (average 23 ± 13.6 months). Evaluated parameters were uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), manifest refraction, pachymetry, slit- lamp examination and corneal topography at baseline and at 1,3,6,12,24 and 48 months. Results We found a nonsignificant improvement in UCVA and BSCVA with a small reduction of manifest cylinder and no significant change in spherical equivalent or K-values. Following CXL, stability of UCVA and BSCVA at the last follow-up examination was found in 71 and 77% of treated eyes, respectively. No permanent adverse events have been recorded throughout the study period. Conclusion In our series, CXL was a safe procedure in the pediatric population. Stabilization of progressive keratoconus was achieved in visual acuity, refractive and topography parameters with no improvement in corneal indices in contrary to adult CXL treatment. How to cite this article Bakshi E, Barequet IS, Aizenman I, Levinger S, Avni I, Zadok D. Corneal Corss-linking in Patients Younger than 18 Years: Long-term Follow-up in Three Israeli Medical Centers. Int J Kerat Ect Cor Dis 2014;3(2):84-87.

Preparation of Polyvinylidene Fluoride (PVDF) Triboelectric Nanogenerators with Different Polymer

2015 ◽  
Vol 814 ◽  
pp. 91-95
Author(s):  
Cheng Wang ◽  
Hao Yu ◽  
Tao Huang ◽  
Chao Tan
Keyword(s):  
Polymer Films ◽  
Polyvinylidene Fluoride ◽  
Low Cost ◽  
Mechanical Energy ◽  
Flexible Polymer ◽  
Surrounding Environment ◽  
Nanofiber Membranes ◽  
External Consistency ◽  
Low Wear ◽  
Triboelectric Nanogenerators

Triboelectric nanogenerators have recently been used to harvest mechanical energy from surrounding environment which is of great significance in the field of energy conversion. Electrospinning provides a simple, low cost and versatile method for the generation of 1D nanostrucutures. Nanofiber membranes have many advantages over the commonly used dense film for designing the riboelectric nanogenerators, such as the low wear resistance caused from the internal and excellent external consistency of the electrospinning membranes. In this paper, we produce a variety of polymer films by electro-spinning, and fabricate Polyvinylidene Fluoride (PVDF) triboelectric nanogenerators with different polymer films afterwards. We except to explore the TEG power generation effect, and influencing factors, and then determine the best combination of the results of TEG (PVDF-PHBV). Such a flexible polymer TEG generates output voltage of up to 112 V at a power of 0.045W.

Boundary Lubricant Polymer Films: Effect of Cross-Linking

Langmuir ◽  
2013 ◽  
Vol 29 (42) ◽  
pp. 12936-12949 ◽  
Author(s):  
Suzanne Giasson ◽  
Jeanne-Marie Lagleize ◽  
Juan Rodríguez-Hernández ◽  
Carlos Drummond
Keyword(s):  
Polymer Films ◽  
Cross Linking ◽  
Boundary Lubricant
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