Ultra high molecular weight polyethylene (UHMWPE) fibers possess outstanding properties such as high tensile strength and low density. However, their low surface polarity and poor heat resistance restrict the application of UHMWPE fibers as a reinforcing material for high performance composites. These shortcomings of UHMWPE fibers can be overcome by ultraviolet (UV) assisted grafting treatment and hybridization with aramid fibers. Results show that UHMWPE fibers could firstly be modified by means of an UV radiation assisted one step grafting process with acetone as solvent and acrylic acid as monomers, then the mechanical properties of composites of epoxy resin with the modified UHMWPE fibers was greatly enhanced; with the increasing monomer content in the acetone solvent, the tensile strength of UHMWPE fibers/epoxy resin composites increased obviously, while there was no significant change of flexural strength and impact strength. In order to further improve the heat resistance of UHMWPE fibers/epoxy resin composites, UHMWPE fibers were hybridized with aramid fibers and then the hybrid fibers were used as reinforcing material to produce hybrid fibers/epoxy resin composites. As a result, the deformation of the hybrid fibers/epoxy resin composites decreased by 66.7% at 90°C compared to that of UHMWPE fibers/epoxy resin composites. The result proves that the pre-hybridization of UHMWPE fibers is an effective means to enhance the heat resistance of UHMWPE fibers/epoxy resin composites .
Abstract Background To evaluate the effect of internal limiting membrane (ILM) peeling surrounding macular holes (MH) for the function of retina by microperimetry-3(MP-3). Methods This is a prospective, cohort study which included patients with MHs who were treated by 23-gauge 3-port pars plana vitrectomy and ILM peeling with air tamponade. Color fundus photography, retinal optical coherence tomography and MP-3 were performed 1 week before, 1 and 4 months after the operation. In MP-3 examination, a customized follow-up pattern with 45 spots in the central 8° visual field was used. The spots corresponding to the retina surrounding macular holes were selected for comparison of pre- and post-operative function. Results We incuded 44 eyes of 44 patients with best corrected visual acuity (BCVA) of 1.06±0.40 (logMAR). All eyes achieved an anatomical success at 4 months. BCVA significantly improved at 1 month (0.53±0.30, P<0.01) and 4 months (0.31±0.24, P<0.01), respectively. Mean retinal sensitivity (MRS, dB) of the retina surrounding macular hole was 23.46±3.01 dB at baseline, and significantly increased at 1 month (26.25±2.31 dB, u=-4.88, P<0.01) and 4 months(27.14±2.45 dB, t=-6.29, P<0.01). Patients with increased MRS are significantly younger than those with deceased MRS (59.72±3.22 years vs. 65.60±8.19 years, P<0.01). After ILM peeling, the increasing extent of MRS was significantly higher in inferior and nasal retina than in superior and temporal retina at 1 and 4 months (P<0.05). Conclusion ILM peeling in normal retina will not decrease the retinal function in a short-term after surgery.
Abstract Background: To compare idiopathic macular holes (IMHs) between male and female before and after surgery. Methods: Patients with IMHs of stage 3 and stage 4 who underwent 23-gauge vitrectomy were retrospectively enrolled. Pre-operative clinical features like age of onset, and best-corrected visual acuity (BCVA) were reviewed. Optical coherence tomography parameters including minimum linear diameter (MLD), central macular thickness and some other indexes were measured and calculated. Main surgical outcomes included the primary closure rate, the highest BCVA during follow-up, and the recovery duration. All the metrics mentioned above were compared between genders with appropriate statistical methods. Results: A total of 298 eyes from 280 patients (male: 51; female: 229) were enrolled. Compared with men, women demonstrated a significantly higher ratio of stage3/stage4 (P=0.045), larger horizontal MLD (P=0.009), but similar surgical outcomes except for a relatively longer recovery duration (P=0.024). For stage 3 IMHs, women exhibited significantly younger age of onset (P=0.023), larger MLD (P=0.003), and smaller height of the hole (P=0.029). However, for stage 4 IMHs, all the pre- and post-operative metrics showed no differences between genders. Conclusions: Female IMHs seem to demonstrate an earlier age of onset and larger size of hole, especially in IMHs of stage 3. However, these differences, which may owe to normal gender-related variations, have limited influence on the surgical outcomes.
Abstract Introduction To evaluate the effect of internal limiting membrane (ILM) peeling surrounding macular holes (MH) for the function of retina by microperimetry-3(MP-3). Materials and Methods This is a prospective, cohort study which included patients with MHs who were treated by 23-gauge 3-port pars plana vitrectomy and ILM peeling with air tamponade. Color fundus photography, retinal optical coherence tomography and MP-3 were performed 1 week before, 1 and 4 months after the operation. In MP-3 examination, a customized follow-up pattern with 45 spots in the central 8° visual field was used. The spots corresponding to the retina surrounding macular holes were selected for comparison of pre- and post-operative function. Results We included 44 eyes of 44 patients with best corrected visual acuity (BCVA) of 1.06±0.40 (logMAR). All eyes achieved an anatomical success at 4 months. BCVA significantly improved at 1 month (0.53±0.30, P<0.01) and 4 months (0.31±0.24, P<0.01), respectively. Mean retinal sensitivity (MRS, dB) of the retina surrounding macular hole was 23.46±3.01 dB at baseline, and significantly increased at 1 month (26.25±2.31 dB, u=-4.88, P<0.01) and 4 months(27.14±2.45 dB, t=-6.29, P<0.01). Patients with increased MRS are significantly younger than those with deceased MRS (59.72±3.22 years vs. 65.60±8.19 years, P<0.01). After ILM peeling, the increasing extent of MRS was significantly higher in inferior and nasal retina than in superior and temporal retina at 1 and 4 months (P<0.05). Conclusion ILM peeling in normal retina will not decrease the retinal function in a short-term after surgery.
Purpose: To compare the efficacy of air and perfluoropropane (C3F8) with pars plana vitrectomy (PPV) in highly myopic macular holes (HMMHs) and explore the factors related to surgical prognosis. Methods: A retrospective comparison of a consecutive series of HMMHs undergone vitrectomy and internal limiting membrane peeling. According to tamponade type, they were divided into air group and C3F8 group, which were further divided into subgroups based on hole diameter or axial length (AXL). Anatomical and functional outcomes were compared between tamponades. Related factors of initial closure rate and postoperative best-corrected visual acuity (BCVA) were analyzed by logistic regression. Results: The baseline characteristics in air group (n = 63) and C3F8 group (n = 37) were similar except the age of air was older ( P = 0.019). The mean follow-up period was 17.16 ± 17.97 months. After surgery, the initial closure rate of air group was 85.7% and that of C3F8 group was 83.7% ( P = 0.780). And the initial closure rate showed no difference between tamponades in the same subgroup classified by hole diameter or AXL (all P > 0.05). Postoperative BCVA improved significantly in both groups ( P < 0.001), but no difference between them ( P = 0.793). Logistic regression showed that age, minimum linear diameter, and AXL were risk factors of initial closure rate, and preoperative BCVA was the only factor associated with postoperative BCVA (all P < 0.05). Conclusion: With a long-term follow-up of HMMH, we found air had a similar tamponade effect anatomically and functionally compared with C3F8. Air may also be a good choice for patients with HMMH.
This study develops a readily implementable surface modification technique for Al alloys by combining electroplating alloy films with depositing stearic acid to make a durable superhydrophobic coating. Selecting Al as anode for electroplating innovatively, the introduction of Al element improves the adherence and roughness of the coating through a principle identical to the reactive element (RE) effect. Al can be preferentially combined with oxygen to reduce the partial pressure of oxygen, inhibiting outward diffusion and oxidation of the electroplated alloy components, reducing the defects formed by the outward diffusion of the metal elements and the accompanying porosity and cracks. Besides, the dense and stable nature of the oxide film formed by RE effect can better protect the Al alloy substrates from oxidation. It is shown that the crystallinity and oxidation resistance of the alloy is significantly enhanced by the RE effect. Notably, the champion water contact angle has reached 162° ± 0.7°, and a significant reduction in surface porosity is observed. This research has the potential to provide a simplified fabrication process of Ni–Cr–W alloy and pave the way for the development of durability of superhydrophobic film.
The high-quality absorber with improved light absorption ability and crystallinity plays a critical role in enhancing the photovoltaic performance of CsPbBr3-based solar cells. This work developed a Bi2S3 nanocrystal–CsPbBr3 hybrid absorber to improve the photovoltaic performance of perovskite solar cells (PSCs) by taking advantages of both CsPbBr3 and Bi2S3. The as-synthesized Bi2S3 nanocrystals with different structures, including quantum dots (QDs) and nanorods (NRs), were applied as the hybridizer of CsPbBr3 by embedding them into the CsPbBr3 matrix, respectively, while the Bi2S3 QDs and NRs were prepared just by adjusting the synthesized times. Ultimately, the CsPbBr3–Bi2S3 NR hybrid absorber enables carbon-based PSCs (C-PSCs) to achieve a champion power conversion efficiency (PCE) of 9.37%, which presents an improvement of 19.7% compared with the PCE of the device based on the pristine CsPbBr3 absorber. The improved photovoltaic performance originated from the enhanced crystallinity, reduced surface defects, broadened light response region in the hybrid absorber, and enhanced carrier separation/transport process in the device. This study provides valuable guidance for the design and assembly of nanocrystal–perovskite hybrid absorbers to improve the photovoltaic performance of CsPbBr3-based solar cells.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
