Characteristics and Clinical Course of Dysphagia Caused by Anterior Cervical Osteophyte

Objective To investigate swallowing characteristics of patients with dysphagia caused by anterior cervical osteophytes (ACOs) and compare clinical courses according to treatment options. Methods A retrospective analysis of 1,866 videofluoroscopic swallowing studies (VFSS) of patients with ACOs from electronic medical records was performed. Patients with other diseases that could explain the dysphagia were excluded. Dysphagia characteristics and severity and clinical and radiological characteristics of subjects with ACOs were evaluated. Dysphagia characteristics and clinical course were compared among three treatment groups: surgical treatment, swallowing rehabilitation, and conservative treatment. Results Subjects were 22 men and 1 woman with a mean age of 78.69±8.01 years. The mean osteophyte thickness was 9.07±3.84 mm. It was significantly thicker in the surgical group than that in other groups (p=0.01). ACOs were most frequently found at C5 level. This level also had the thickest osteophytes. However, videofluoroscopic dysphagia scales (VDS) were not significantly different among the three treatment groups. The pharyngeal phase score of the VDS was significantly higher in the surgical group (p=0.041). Dysphagia severity was decreased significantly in the surgical group at 3 months after the initial VFSS (p=0.004). Conclusion The main swallowing characteristics in patients with ACOs were dysphagia features of the pharyngeal phase, including inappropriate airway protection, decreased laryngeal elevation, and reduced epiglottis inversion. When determining treatment options, it may be helpful to consider dysphagia severity at pharyngeal phase and osteophyte thickness

Conductive GelMA–Collagen–AgNW Blended Hydrogel for Smart Actuator

Blended hydrogels play an important role in enhancing the properties (e.g., mechanical properties and conductivity) of hydrogels. In this study, we generated a conductive blended hydrogel, which was achieved by mixing gelatin methacrylate (GelMA) with collagen, and silver nanowire (AgNW). The ratio of GelMA, collagen and AgNW was optimized and was subsequently gelated by ultraviolet light (UV) and heat. The scanning electron microscope (SEM) image of the conductive blended hydrogels showed that collagen and AgNW were present in the GelMA hydrogel. Additionally, rheological analysis indicated that the mechanical properties of the conductive GelMA–collagen–AgNW blended hydrogels improved. Biocompatibility analysis confirmed that the human umbilical vein endothelial cells (HUVECs) encapsulated within the three-dimensional (3D), conductive blended hydrogels were highly viable. Furthermore, we confirmed that the molecule in the conductive blended hydrogel was released by electrical stimuli-mediated structural deformation. Therefore, this conductive GelMA–collagen–AgNW blended hydrogel could be potentially used as a smart actuator for drug delivery applications

Decoupling Charge Transfer and Transport at Polymeric Hole Transport Layer in Perovskite Solar Cells

Tailoring charge extraction interfaces in perovskite solar cells (PeSCs) critically determines the photovoltaic performance of PeSCs. Here, we investigated the decoupling of two major determinants of the efficient charge extraction, the charge transport and interfacial charge transfer properties at hole transport layers (HTLs). A simple physical tuning of a representative polymeric HTL, poly­(3,4-ethylene­dioxy­thiophene):poly­(styrenesulfonate), provided a wide range of charge conductivities from 10^–4 to 10³ S cm^–1 without significant modulations in their energy levels, thereby enabling the decoupling of charge transport and transfer properties at HTLs. The transient photovoltaic response measurement revealed that the facilitation of hole transport through the highly conductive HTL promoted the elongation of charge carrier lifetimes within the PeSCs up to 3 times, leading to enhanced photocurrent extraction and finally 25% higher power conversion efficiency

Soft luminescent solar concentrator film with organic dye and rubbery matrix

We propose a soft luminescent solar concentrator (LSC) with superior light propagation. The rubbery poly(ethylene-co-vinyl acetate) (EVA) was adopted to replace the conventional brittle poly(methyl methacrylate) (PMMA). We analyzed the transmittance, photoluminescence efficiency, crystallinity, and surface properties of LSC to understand the optical and structural properties of the LSC. In addition, we modified the optical slab model to provide insights into the optical phenomenon in plate-type LSC devices; we evaluated the solar absorption efficiency of the glass and emitting layers. We also evaluated the solar concentration performances of the LSC devices by measuring the photocurrent density generated using a monocrystalline silicon solar cell. We compared the transporting ability of emitted light into an edge by calculating the collection efficiency based on the concentration factor and optical efficiencies (absorption and photoluminescence). The concentration factor, optical efficiency, and collection efficiency of the EVA-LSC with 4000 ppm of Lumogen F Red 305 were 0.31, 3.1, and 40%, respectively. The overall optical properties of the EVA-LSC were comparable to those of the PMMA-LSC. Moreover, the light decay property of EVA-LSC was superior by 1.2 times than PMMA-LSC. Therefore, we suggest EVA can replace PMMA and be used for flexible and large-area LSC applications