University of Toyama

A research consortium made a recent discovery that the natural molecule trigonelline present in coffee, fenugreek, and also in the human body, can help to improve muscle health and function. A research consortium led by Nestlé Research in Switzerland and the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine) made a recent discovery that the natural molecule trigonelline present in coffee, fenugreek, and also in the human body, can help to improve muscle health and function. In an international collaboration among the University of Southampton, University of Melbourne, University of Tehran, University of South Alabama, University of Toyama and University of Copenhagen, the work builds on a previous collaborative study that described novel mechanisms of human sarcopenia. Sarcopenia is a condition where cellular changes that happen during ageing gradually weaken the muscles in the body and lead to accelerated loss of muscle mass, strength and reduced physical independence. One important problem during sarcopenia is that the cellular cofactor NAD+ declines during ageing, while mitochondria, the energy powerhouses in our cells, produce less energy. The study team discovered that levels of trigonelline were lower in older people with sarcopenia. Providing this molecule in pre-clinical models resulted in increased levels of NAD+, increased mitochondrial activity and contributed to the maintenance of muscle function during ageing. NAD+ levels can be enhanced with different dietary precursors like the essential amino acid L-tryptophan (L-Trp), and vitamin B3 forms such as nicotinic acid (NA), nicotinamide (NAM), nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN). Assistant Professor Vincenzo Sorrentino from the Healthy Longevity Translational Research Programme at NUS Medicine added, "Our findings expand the current understanding of NAD+ metabolism with the discovery of trigonelline as a novel NAD+ precursor and increase the potential of establishing interventions with NAD+-producing vitamins for both healthy longevity and age-associated diseases applications." Nutrition and physical activity are important lifestyle recommendations to maintain healthy muscles during ageing. "We were excited to discover through collaborative research that a natural molecule from food cross-talks with cellular hallmarks of ageing. The benefits of trigonelline on cellular metabolism and muscle health during ageing opens promising translational applications," said Jerome Feige, Head of the Physical Health department at Nestlé Research.

An upconversion organic light-emitting diode (OLED) based on a typical blue-fluorescence emitter achieves emission at an ultralow turn-on voltage of 1.47 V. The technology circumvents the traditional high voltage requirement for blue OLEDs, leading to potential advancements in commercial smartphone and large screen displays. An upconversion organic light-emitting diode (OLED) based on a typical blue-fluorescence emitter achieves emission at an ultralow turn-on voltage of 1.47 V, as demonstrated by researchers from Tokyo Tech. Their technology circumvents the traditional high voltage requirement for blue OLEDs, leading to potential advancements in commercial smartphone and large screen displays. Blue light is vital for light-emitting devices, lighting applications, as well as smartphone screens and large screen displays. However, it is challenging to develop efficient blue organic light-emitting diodes (OLEDs) owing to the high applied voltage required for their function. Conventional blue OLEDs typically require around 4 V for a luminance of 100 cd/m2; this is higher than the industrial target of 3.7 V -- the voltage of lithium-ion batteries commonly used in smartphones. Therefore, there is an urgent need to develop novel blue OLEDs that can operate at lower voltages. In this regard, Associate Professor Seiichiro Izawa from Tokyo Institute of Technology and Osaka University, collaborated with researchers from University of Toyama, Shizuoka University, and the Institute for Molecular Science has recently presented a novel OLED device with a remarkable ultralow turn-on voltage of 1.47 V for blue emission and a peak wavelength at 462 nm (2.68 eV). Their work will be published in Nature Communications. The choice of materials used in this OLED significantly influences its turn-on voltage. The device utilizes NDI-HF (2,7-di(9H-fluoren-2-yl)benzo[lmn][3,8]-phenanthroline-1,3,6,8(2H,7H)-tetraone) as the acceptor, 1,2-ADN (9-(naphthalen-1-yl)-10-(naphthalen-2-yl)anthracene) as the donor, and TbPe (2,5,8,11-tetra-tert-butylperylene) as the fluorescent dopant. This OLED operates via a mechanism called upconversion (UC). Herein, holes and electrons are injected into donor (emitter) and acceptor (electron transport) layers, respectively. They recombine at the donor/acceptor (D/A) interface to form a charge transfer (CT) state. Dr. Izawa points out: "The intermolecular interactions at the D/A interface play a significant role in CT state formation, with stronger interactions yielding superior results." Subsequently, the energy of the CT state is selectively transferred to the low-energy first triplet excited states of the emitter, which results in blue light emission through the formation of a high-energy first singlet excited state by triplet-triplet annihilation (TTA). "As the energy of the CT state is much lower than the emitter's bandgap energy, the UC mechanism with TTA significantly decreases the applied voltage required for exciting the emitter. As a result, this UC-OLED reaches a luminance of 100 cd/m2, equivalent to that of a commercial display, at just 1.97 V," explains Dr. Izawa. In effect, this study efficiently produces a novel OLED, with blue light emission at an ultralow turn-on voltage, using a typical fluorescent emitter widely utilized in commercial displays, thus marking a significant step toward meeting the commercial requirements for blue OLEDs. It emphasizes the importance of optimizing the design of the D/A interface for controlling excitonic processes and holds promise not only for OLEDs but also for organic photovoltaics and other organic electronic devices.