Submicron-Thickness Ultraflexible Organic Light-Emitting Diodes via a Photoregulated Stripping Strategy.

With the rapid advances in imperceptible and epidermal electronics, the research on ultraflexible organic light-emitting diodes (OLEDs) has become increasingly significant, owing to their excellent flexibility and conformability to the human body. It is highly desirable to develop submicrometer-thick ultraflexible OLEDs to enable the devices to seamlessly conform to the surface of arbitrary-shaped objects and still function properly. However, it remains a huge challenge for currently reported OLEDs due to the lack of an appropriate stripping strategy. Here, for the first time, we develop a facile photoregulated stripping strategy for the fabrication of high-performance ultraflexible OLEDs with submicron thickness. Under ultraviolet (UV) irradiation, the surface adhesion force of the ultrathin photopolymer membrane can be adjusted from 16.9 to 5.1 N/m, thereby effectively controlling the laminating and detaching process. Based on this strategy, the resultant device thickness is as low as 0.821 µm, which is the lowest record among flexible OLEDs reported to date. More remarkably, excellent electrical properties with a maximum current efficiency (CE) of 62.5 cd/A, an external quantum efficiency (EQE) of 17.8%, and a low turn-on voltage of 2.5 V are realized, which are superior to almost all of the reported ultraflexible OLEDs with thicknesses below 10 µm. Based on versatile ultraflexible OLEDs, all-organic and skin-mounted displays are successfully realized by employing a conformable organic thin-film transistor (OTFT) as the driver. This work offers a feasible strategy for advancing OLEDs from flexible to ultraflexible, showing significant application potential in future epidermal electronics and conformal displays.

Air/Liquid Interfacial Self-Assembled Intrinsically Stretchable IDT-BT Film Combining a Deliberate Transfer Adherence Strategy for Stretchable Electronics.

Indacenodithiophene-benzothiadiazole (IDT-BT) has emerged as one of the most promising candidates for stretchable electronics due to its good stretchability and high mobility. Here, we present an air/liquid interface self-assembly method for the stretchable IDT-BT films and design an air-side transfer adherence strategy for improving the carrier mobility of IDT-BT. By controlling the cosolvent ratio in solution and the solvent evaporation rate, the large-scale intrinsically stretchable IDT-BT film with the diameter as high as ∼3 cm was self-assembled at the air/liquid interface. The resulting stretchable film with lightweight and good uniformity could be easily transferred to curved objects such as flexible 3 M tape, glass ball, and seashell. It is found that the transfer adherence strategy of the semiconductor film significantly affects the carrier transport. The transfer adherence from air-side can effectively decrease the number of the adsorbed water molecules at semiconductor/dielectric interface, which presents the mobility as high as 2.98 cm2 V-1 s-1. Based on the air/liquid interface self-assembled IDT-BT film, the peeling process of the film for preparation of full stretchable transistors could be eliminated. The resulting intrinsically stretchable transistor exhibits mobility higher than that of the transistor with a conventional spin-coated film. Our research provides new pathways for preparing the stretchable films and intrinsically stretchable organic field-effect transistors and shows the promising potential of the air/liquid interface self-assembly strategy for stretchable electronics.

Multimodal-Synergistic-Modulation Neuromorphic Imaging Systems for Simulating Dry Eye Imaging.

Inspired by human eyes, the neuromorphic visual system employs a highly efficient imaging and recognition process, which offers tremendous advantages in image acquisition, data pre-processing, and dynamic storage. However, it is still an enormous challenge to simultaneously simulate the structure, function, and environmental adaptive behavior of the human eye based on one device. Here, a multimodal-synergistic-modulation neuromorphic imaging system based on ultraflexible synaptic transistors is successfully presented and firstly simulates the dry eye imaging behavior at the device level. Moreover, important functions of the human visual system in relation to optoelectronic synaptic plasticity, image erasure and enhancement, real-time preprocessing, and dynamic storage are simulated by versatile devices. This work not only simplifies the complexity of traditional neuromorphic visual systems, but also plays a positive role in the publicity of biomedical eye care.

High-Mobility Fungus-Triggered Biodegradable Ultraflexible Organic Transistors.

Biodegradable organic field-effect transistors (OFETs) have drawn tremendous attention for potential applications such as green electronic skins, degradable flexible displays, and novel implantable devices. However, it remains a huge challenge to simultaneously achieve high mobility, stable operation and controllable biodegradation of OFETs, because most of the widely used biodegradable insulating materials contain large amounts of hydrophilic groups. Herein, it is firstly proposed fungal-degradation ultraflexible OFETs based on the crosslinked dextran (C-dextran) as dielectric layer. The crosslinking strategy effectively eliminates polar hydrophilic groups and improves water and solvent resistance of dextran dielectric layer. The device with spin-coated 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) semiconductor and C-dextran dielectric exhibits the highest mobility up to 7.72 cm2 V-1 s-1 , which is higher than all the reported degradable OFETs. Additionally, the device still maintains high performance regardless of in an environment humidity up to 80% or under the extreme bending radius of 0.0125 mm. After completion of their mission, the device can be controllably biodegraded by fungi without any adverse environmental effects, promoting the natural ecological cycles with the concepts of "From nature, for nature". This work opens up a new avenue for realizing high-performance biodegradable OFETs, and advances the process of the "green" electrical devices in practical applications.

Suppressing Interface Strain for Eliminating Double-Slope Behaviors: Towards Ideal Conformable Polymer Field-Effect Transistors.

High-mobility polymer field-effect transistors (PFETs) are being actively explored for applications in soft electronic skin and low-cost flexible displays because of their superior solution processability, mechanical flexibility, and stretchability. However, most of high-mobility PFETs often deviate from the idealized behavior with variable mobility, large threshold voltage, and high off-state current, which masks their intrinsic properties and significantly impedes their practical applications. Here, it is first revealed that interface strain between polymer thin film and rigid substrate plays a crucial role in determining the ideality of PFETs, and demonstrate that various ideal conformable PFETs can be successfully fabricated by releasing strain. It is found that strain in film can be released by one-step peeling strategy, which can reduce π-π stacking distance and suppress generation of oxygen doped carriers, thereby obtaining linearly injected charge carriers and decreased carrier concentration in channel, eventually realizing ideal PFETs. More impressively, the fabricated ideal conformable PFET array displays outstanding conformability to curved objects, and meanwhile showing excellent organic light-emitting display driving capability. The work clarifies the effect of the interface strain on the device ideality, and strain can be effectively released by a facile peeling strategy, thus offering useful guidance for the construction of ideal conformable PFETs.

High-Performance Full-Photolithographic Top-Contact Conformable Organic Transistors for Soft Electronics.

Organic thin-film transistors (OTFTs) are identified to be the most promising candidate for next-generation wearable and implantable electronics because of their unique advantages including their flexibility, low cost, long-term biocompatibility, and simple packaging. However, commercialization of organic transistors remains an enormous challenge due to their low mobility and lack of scalable strategy for high-precise soft devices. Here, a novel photolithography fabrication strategy is proposed, which is completely compatible with various commercial organic semiconductor materials, for the first demonstration of the fully photolithographic top-contact conformable OTFTs with the device density as high as 1523 transistors cm-2. Excellent electrical and mechanical properties with device yield as high as 100%, field-effect mobility up to 1-2 cm2 V-1 s-1, and outstanding conformability are shown. This work provides a new strategy that can fully maximize the advantages of organic materials and photolithography technology, showing a great prospect in the development of high-performance, high-precise organic devices toward the commercialized and industrialized soft electronic products.

Reciprocity in Quarantine: Observations from Wuhan's COVID-19 Digital Landscapes.

The 2003 SARS pandemic heralded the return of quarantine as a vital part of twenty-first century public health practice. Over the last two decades, MERS, Ebola, and other emerging infectious diseases each posed unique challenges for applying quarantine ethics lessons learned from the 2003 SARS-CoV-1 outbreak. In an increasingly interdependent and connected global world, the use of quarantine to contain the spread of SARS-CoV-2, or COVID-19, similarly poses new and unexpected ethical challenges. In this essay, we look beyond standard debates about the ethics of quarantine and state power to explore a key quarantine principle, Reciprocity, and how it is being negotiated by healthcare workers, volunteers, and citizens in the context of the Wuhan, China, quarantine. We analyze Reciprocity through the lens of two Wuhan case studies: (1) healthcare workers, particularly nurses, who are simultaneously essential workers and quarantined citizens, asked by their hospital administration to shave their heads because adequate PPE was not available, and (2) citizen-to-citizen mutual aid societies attempting to fill gaps in essential supplies left unfilled by the state. We analyze social media and video-blogs from Wuhan, on the platforms of Douyin and Sina Weibo, to understand how people define and respond to ethical and legal obligations in the wake of COVID-19. It is no surprise that quarantine principles from the 2003 SARS outbreak are inadequate for COVID-19 and that both infectious disease outbreak responses and ethics must adapt to the virtual age. We offer ideas to strengthen and clarify Reciprocal obligations for the state, hospital administrators, and citizens as the globe prepares for the next wave of COVID-19 circulating now.

Effects of Trimetazidine Pretreatment on Endothelial Dysfunction and Myocardial Injury in Unstable Angina Patients Undergoing Percutaneous Coronary Intervention.

OBJECTIVES: Trimetazidine is an anti-ischemic medication licensed for the treatment of angina pectoris. However, the molecular mechanisms underlying its action remain incompletely elucidated. In this study, therefore, we examined the potential beneficial effects of trimetazidine on myocardial injury and endothelial dysfunction in patients with unstable angina in the perioperative period of percutaneous coronary intervention (PCI). METHODS: A total of 97 patients with unstable angina were randomly divided into trimetazidine (n = 48) and control (n = 49) groups. All subjects received standard medical therapy. The trimetazidine group additionally received 20 mg trimetazidine three times daily 24 hours before and after PCI. Serum levels of creatine kinase-muscle/brain (CK-MB), cardiac troponin I (cTnI), heart-type fatty acid-binding protein (h-FABP), von Willebrand factor (vWF), and nitric oxide (NO) were measured before and the morning following PCI. RESULTS: In the control group, levels of CK-MB, cTnI, and vWF were significantly elevated (P < 0.05) and NO level was decreased after PCI (P < 0.05). By contrast, no significant changes in the levels of these proteins were observed in the trimetazidine group after PCI (P > 0.05). Moreover, h-FABP levels were not significantly altered after PCI whether in the control or in the trimetazidine group (P > 0.05). Finally, a time-dependent increase in the levels of h-FABP from 0 to 6 hours after PCI, followed by a progressive decline, was observed (P < 0.05). CONCLUSIONS: PCI induces endothelial dysfunction and myocardial damage in patients with unstable angina. Trimetazidine therapy in the perioperative period can reduce this damage.

MiR-21 suppresses ox-LDL-induced HUVECs apoptosis by targeting PDCD4.

This study was to investigate the effects of microRNA-21 (miR-21) on ox-LDL-induced HUVECs apoptosis. MTT assay was performed to evaluate the proliferation of HUVECs. Quantitative RT-PCR was conducted to quantify the expression of miR-21. Western blotting was used to determine protein expression. Annexin V/propidium iodide double staining was adopted to detect cell apoptosis. We found that ox-LD significantly induced HUVECs apoptosis and reduced miR-21 expression. MiR-21 mimic attenuated the apoptosis of HUVECs under ox-LDL treatment compared with the NC groups while miR-21 inhibitors promoted that of HUVECs. MiR-21 directly targeted PDCD4 in HUVECs. Moreover, miR-21 significantly regulated the downstream apoptotic proteins like bax, bad, bcl-2 and caspase3, meanwhile it enhanced the phosphorylation of ERK.

Cardioprotective effects of traditional Chinese medicine Guanmaitong on acute myocardial infarction.

Guanmaitong (GMT) is a traditional Chinese herbal compound that has been used for the treatment of coronary heart disease (CHD) and other cardiovascular diseases. However, the efficacy of GMT in treating cardiovascular diseases remains unclear. The aim of the present study was to investigate the protective mechanisms and identify the targeted proteins and signaling networks associated with the physiological activity of GMT in a rat model of acute myocardial infarction (AMI). Sprague-Dawley rats were randomly allocated into five groups: Control group (sham-operated), the model group, and small, medium, and large dosage GMT groups. The rat model of AMI was established via ligation of the coronary artery. The results indicate that GMT was able to reduce myocardial infarction size and improve the activities of tumor necrosis factor-α (TNF-α), intercellular adhesion molecule 1 (ICAM-1) and interleukin-1. Furthermore, the reduced apoptotic index of the GMT-treated cardiocytes (P<0.05 vs. model group) was in accordance with the downregulated expression of Bax and the upregulated expression of Bcl-2. In conclusion, GMT may exert a protective potential against myocardial infarction injury by inhibiting apoptosis and inflammation of cardiomyocytes, and may offer a promising adjunct treatment for CHD.