Science Exploration Press

White-color organic light-emitting diodes (WOLEDs) have aroused wide interests for future lighting because of low energy consumption in principle, while still suffer from the degradation by Joule heating and polaron-induced quenching under high luminance caused by high current in practical. To obtain high current efficiency, which means high luminance at low current density, tandem WOLEDs with multiple electroluminescence (EL) units connected in series with charge generation layers (CGLs) have been developed. Here we report the improved hybrid tandem WOLED with two EL units, EL1 and EL2, where EL1 and EL2 generate fluorescent blue and phosphorescent yellow emissions from a metal-free material BCzVBi and a Ir-complex (fbi)₂Ir(acac), respectively, with CGL composed of a HATCN/NPB bilayer. The white-light emitting device shows the maximum current efficiency and power efficiency of 60.2 cd/A and 29.6 lm/W, respectively, without out-coupling structure. A low driving voltage of 6.5 V at 1,000 cd/m² is realized, which is an important value because such a luminance is required for actually employed lighting device. The blue emission appears from 5.4 V, and the light color changes from yellowish to bluish white during 5.4 V to 13.4 V, which could be explained by the energy level structures of the device and proved by the J-V characteristics. Additionally, this tandem WOLED also shows photovoltaic effect. This work provides a design of room light source whose color temperature could be tuned through applied voltage when needed, and a display system for low-current operated amorphous Si-TFT due to its high current efficiency.

Blue emitters are highly desired in organic light-emitting diodes (OLEDs), but their electroluminescence efficiencies and roll-offs are always less than satisfactory. In this work, a triazine-based deep-blue emitter (2PhCzTRZ-Cz) is designed and synthesized. It prefers high thermal stability with a decomposition temperature of up to 543 °C, and possesses strong deep-blue photoluminescence. The doped OLEDs using 2PhCzTRZ-Cz as an emitter attain deep-blue lights at 418-424 nm, with high maximum external quantum efficiencies (η_exts) of 4.46-5.68%, maximum luminances of 2,820-7,400 cd m^-2, CIE_y values < 0.1 and small efficiency roll-offs. In addition, multiple-resonance thermally activated delayed fluorescence OLED by using 2PhCzTRZ-Cz as host realizes a high maximum η_ext of 21.5%, significantly higher than those of the device based on traditional mCBP host (12.9%). These outstanding performances demonstrate the great potential of 2PhCzTRZ-Cz as an emitter and host for OLEDs.

With the development of 3D printing technologies, cellulose has been explored to realize its sophisticated geometry fabrication in this field for a variety of applications. This review focuses specifically on the latest research progress of 3D printing cellulose by discussing the characteristics of cellulose materials, different 3D printing technologies, and their optimal performance for applications in various fields like biomedicine, food packaging, and tissue engineering. The challenges of preparing 3D printing "ink" of cellulose using dissolved cellulose or nanocellulose are introduced. Finally, the corresponding applications of cellulose using 3D printing are classified and the strategies to optimize production performance are provided.

Aims: Recent world events have resulted in companies using remote meeting tools more often in design processes. The shift to remote meeting tools has had a notable impact on collaborative design activities, such as design reviews (DRs). When DRs depend on computer-aided design (CAD) software, the lack of direct support for CAD functionalities in videoconferencing applications introduces novel communication challenges, i.e. friction. This study investigates friction encountered in real world remote DRs when using a combination of standard CAD and videoconferencing applications. The objective was to understand the main sources of friction when carrying out DRs using a combination of CAD and videoconferencing applications.

Methods: At a single Swedish automobile manufacturer, 15 DRs of a fixture component were passively observed. These observations were subjected to a qualitative thematic analysis to identify categories and sources of friction during these DRs. The DRs were carried out using a combination of CATIA CAD software and Microsoft Teams for videoconferencing.

Results: The analysis of the 15 remote DRs identified four recurring friction categories: requesting specific viewpoints, indicating specific elements, expressing design change ideas, and evaluating ergonomics. Each category highlights specific challenges that were observed during the DRs and emerged due to constraints imposed by existing methods and technologies for remote meetings.

Conclusion: This study provides a framework for understanding the current sources of friction in remote DRs using videoconferencing tools. These insights can support the future development of DR software tools, guiding the integration of features that address these friction points. Additionally, the results serve as a guideline for organizations to implement methods that reduce friction in remote DRs and improve DR quality and efficacy.

Aim: The present study aims to understand the perception of a set of qualified stakeholders regarding the implementation of 4.0 technologies and the subsequent necessary government actions and benefits for citizens. This focus is driven by the transformative impact of the Fourth Industrial Revolution (Industry 4.0), which is revolutionizing healthcare through the integration of digital, physical, and biological technologies.

Methods: This study examines the views of 70 healthcare stakeholders from 33 countries on government actions and citizen benefits associated with these advancements.

Results: The results show significant differences in governmental responses to advancements in healthcare. Some governments struggle to adapt due to outdated strategies, limited investment, and conservative regulations. Others, however, are modernizing their operations, updating regulations, and encouraging innovation. Industry 4.0 technologies enhance healthcare accessibility by offering real-time access to health information and services, especially for remote and underserved populations. These technologies enable citizens to take an active role in managing their health, resulting in better outcomes and an improved quality of life.

Conclusion: The study underscores the need for agile regulatory frameworks to address issues such as data ownership, privacy, and cybersecurity. Governments that embrace Industry 4.0 and update their regulatory frameworks are better equipped to harness the benefits of the Fourth Industrial Revolution in healthcare.

This mini-review explores advancements in the synthesis of nano-carrier-based drug delivery systems using microfluidic chip technology and their evaluation using tumor organ-on-a-chip models. We discuss the principles and advantages of hydrodynamic fluid focusing (HFF) and micromixer for synthesizing polymeric nano-carriers, highlighting their ability to precisely control particle size, shape, and surface properties. The functionalization of nano-carriers for targeted drug delivery is also explored, emphasizing the potential for personalized medicine. The review emphasizes the use of tumor organ-on-a-chip models for evaluating nano-carrier-based drug delivery systems, highlighting their ability to simulate physiological environments and provide dynamic and controllable evaluation platforms. This approach holds great promise for enhancing our understanding of drug behaviors and accelerating the translation of nanomedicines from bench to bedside.