1,720,980 research outputs found
Highly Efficient Organic Light-Emitting Diode Using DNA as Scattering Layer
No full textHerein, an organic light-emitting diode (OLED) is fabricated with increased luminous efficiency and biocompatibility by topographic DNA film. In addition to the natural abundance and biocompatibility of DNA, its semi-flexible characteristics facilitated the emergence of the liquid crystal phase, allowing the formation of a periodic wavy undulation structure by applying shear force. The resultant zigzag structure possesses sufficient periodicity and roughness, enhancing the effective scattering of emitted light. Furthermore, the DNA-coated red OLED demonstrates cell proliferative effects and exhibits high electrical and thermal stability even in a bent state, suggesting its potential application in attachable OLED-based light therapy.
A Wireless and Reusable OLED Patch for Accelerated In Vivo Skin Wound Healing
No full textA fully wireless and reusable red organic light-emitting diode (OLED) patch was developed as a noninvasive platform for skin wound phototherapy. The device integrates a USB-C rechargeable battery, a flexible printed circuit board, and a red OLED emitter into a soft, skin-conformal form factor. The OLED delivers uniform 645 nm light with minimal heat (similar to 21 degrees C) and stable radiance (21.3 W/sr/m2) over 500 h. In a murine full-thickness wound model, a single session of irradiation (2.6-3.9 J/cm2) significantly accelerated wound closure, increased collagen synthesis, and enhanced epidermal differentiation. Immunohistochemical analysis further confirmed reduced inflammation and improved tissue maturation. Unlike previous OLED-based systems that required rigid encapsulation or wired power, this patch enables convenient, home-based light therapy without clinical supervision. The platform demonstrates strong potential as an electroceutical device for personalized dermatologic care and regenerative medicine.
Transition metal-based NIR material with heteroleptic structure for bio-medical application
No full textTransition Metal-Based NIR Material with Heteroleptic Structure for Bio-Medical Application
No full textAmong the near-infrared (NIR) ranges, the area between 700 nm and 1000 nm, called the optical tissue window, is widely used in the bio-medical field because it has less scatter with skin cells and can penetrate deep into the skin to promote cell metabolism. However, it is very challenging to develop a low-gap organic material that emits light in the NIR region due to the increased proportion of non-radiative decay rate by the energy gap law. In order to overcome this hurdle, various types of development methods are being studied such as the use of thermally activated delayed fluoresce (TADF) and transition metal-based phosphorescent materials. In this study, a novel Ir(III) complex was synthesized and designed using a thienothiophene moiety. This material is composed of a fused thiophene structure, and thus is exceedingly rigid and has an extended construction length, thereby reducing the energy gap. In addition, since it has a high electron density structure, the covalent bond between the ligand and iridium can be strengthened to provide stability to the device. Moreover, dipole moments are more likely to be horizontally oriented in heteroleptic structures than in homogeneous structures, thus boosting the performance of the device. Notably, it has a lower non-radiative decay rate than other reported Ir(III)-based NIR emitters. The radiative lifetime is 660 ns, allowing for efficient luminescence with a narrow energy gap. To demonstrate the properties of this novel material, a NIR OLED was fabricated with an emission peak of 700 nm. This optoelectronic device has a very high radiant emittance and a stable operation lifetime
with a Lambertian light distribution. It exhibits excellent electrical and optical properties compared to previously reported Ir(III)-based NIR OLEDs. Furthermore, significant proliferation results were verified compared to the control group in fibroblast cell experiments
Human‐Centric, Three Dimensional Micro Light‐Emitting Diodes for Cosmetic and Medical Phototherapy
No full textAbstract Phototherapy based on micro light‐emitting diodes (µLEDs) has gained enormous attention in the medical field as a patient‐friendly therapeutic method due to its advantages of minimal invasiveness, fewer side effects, and versatile device form factors with high stability in biological environment. Effective cosmetic and medical phototherapy depends on deep light penetration, precise irradiation, and simultaneous multi‐site stimulation, facilitated by three‐dimensional (3D) optoelectronics specifically designed for complex human matters, defined here as 3D µLEDs. This perspective article aims to present the functionalities and strategies of 3D µLEDs for human‐centric phototherapy. This study investigates the effectiveness of phototherapy enabled by three key functionalities such as shape morphing, self‐adaptation, and multilayered spatiotemporal mapping of 3D µLEDs. Finally, this article provides future insights of 3D µLEDs for human‐centric phototherapy applications
Wearable and Wavelength-Tunable Near-Infrared Organic Light-Emitting Diodes for Biomedical Applications
No full textNear-infrared organic light-emitting diodes (NIR OLEDs) have significant potential for wearable phototherapeutic applications because of the unique properties of the OLEDs, including their free-form electronics and the excellent biomedical effects of NIR emission. In spite of their tremendous promise, given that the majority of NIR OLEDs in previous research have relied on the utilization of an intrinsically brittle indium tin oxide (ITO) electrode, their practicality in the field of wearable electronics is inherently constrained. Here, we report wearable and wavelength-tunable NIR OLEDs that employ a high-performance NIR emitter and an innovative architecture by replacing the ITO with a silver (Ag) electrode. The NIR OLEDs permit wavelength tuning of emissions from 700 to 800 nm and afford stable operation even under repeated bending conditions. The NIR OLEDs provide a lowered device temperature of 37.5 C-degrees even during continuous operation under several emission intensities. In vitro experiments were performed with freshly fabricated NIR OLEDs. The outcomes were evaluated against experimental results performed using the same procedure utilizing blue, green, and red OLEDs. When exposed to NIR light irradiation, the promoting effect of cell proliferation surpassed the proliferative responses observed under the influence of visible light irradiation. The proliferation effect of human hair follicle dermal papilla cells is clearly related to the irradiation wavelength and time, thus underscoring the potential of wavelength-tunable NIR OLEDs for efficacious phototherapy. This work will open novel avenues for wearable NIR OLEDs in the field of biomedical application.
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
