Narrowband organic light-emitting diodes for fluorescence microscopy and calcium imaging

Funding: Leverhulme Trust (RPG-2017-231), the EPSRC NSF-CBET lead agency agreement (EP/R010595/1, 1706207), the DARPA NESD program (N66001-17-C-4012) and the RS Macdonald Charitable Trust. C.M. acknowledges funding from the European Commission through a Marie Skłodowska Curie individual fellowship (703387). A.M. acknowledges funding through an individual fellowship of the Deutsche Forschungsgemeinschaft (404587082). Y.D. acknowledges support from the Chinese Scholarship Council (CSC). L.T. acknowledges studentship funding through the EPSRC CM-CDT (EP/L015110/1). M.S. acknowledges funding by the Royal Society (Dorothy Hodgkin Fellowship, DH160102).Fluorescence imaging is an indispensable tool in biology, with applications ranging from single‐cell to whole‐animal studies and with live mapping of neuronal activity currently receiving particular attention. To enable fluorescence imaging at cellular scale in freely moving animals, miniaturized microscopes and lensless imagers are developed that can be implanted in a minimally invasive fashion; but the rigidity, size, and potential toxicity of the involved light sources remain a challenge. Here, narrowband organic light‐emitting diodes (OLEDs) are developed and used for fluorescence imaging of live cells and for mapping of neuronal activity in Drosophila melanogaster via genetically encoded Ca2+ indicators. In order to avoid spectral overlap with fluorescence from the sample, distributed Bragg reflectors are integrated onto the OLEDs to block their long‐wavelength emission tail, which enables an image contrast comparable to conventional, much bulkier mercury light sources. As OLEDs can be fabricated on mechanically flexible substrates and structured into arrays of cell‐sized pixels, this work opens a new pathway for the development of implantable light sources that enable functional imaging and sensing in freely moving animals.PostprintPeer reviewe

The role of metallic dopants in improving the thermal stability of the electron transport layer in organic light-emitting diodes

This research was financially supported by the EPSRC NSF - CBET lead agency agreement (EP/R010595/1, 1706207), the DARPA-NESD program (N66001-17-C-4012) and by the EPSRC CDT Capital Equipment funding stream (EP/L017008/1). C.- M.K. acknowledges support from Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2017R1A6A3A03012331). C.M. acknowledges funding by the European Commission through a Marie Skłodowska Curie Individual Fellowship (703387). Y.D., W.L., and M.W. acknowledge stipends from the Chinese Scholarship Council (CSC). I.D.W.S. acknowledges support from a Royal Society Wolfson research merit award.4,7‐Diphenyl‐1,10‐phenanthroline (BPhen) is widely used to create the electron transport layer (ETL) in organic light‐emitting diodes (OLEDs) because of its high electron mobility and good compatibility with alkali metal n‐dopants. However, the morphology of these ETLs is easily altered by heating due to the relatively low glass transition temperature (Tg) of BPhen and this change often reduces the performance of OLEDs. Here, an enhancement in the thermal stability of OLEDs when doping their BPhen‐based ETLs with cesium (Cs) is reported. To investigate the role of the Cs dopant in the BPhen matrix, the crystallization features of Cs‐doped BPhen films with different doping concentrations are examined. Next, the electrical and optical properties of blue fluorescent and red phosphorescent OLEDs containing Cs‐doped BPhen ETLs are characterized after annealing the OLEDs at temperatures up to 100 °C. Cs plays a critical role in inhibiting the undesired crystallization of BPhen films, which enhances the thermal stability of OLEDs beyond the Tg of neat BPhen. Finally, highly stable BPhen‐based OLEDs encapsulated via atomic layer deposition at 80 °C are demonstrated. This work may lead to a new strategy for enhancing the intrinsic thermal durability of organic devices and their compatibility with thermally demanding processes.PostprintPeer reviewe

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Development of very high luminance p–i–n junction-based blue fluorescent organic light-emitting diodes

This research was financially supported by the EPSRC NSF‐CBET lead agency agreement (EP/R010595/1, 1706207), the DARPA‐NESD programme (N66001‐17‐C‐4012), and the Leverhulme Trust (RPG‐2017‐231). Y.L.D. acknowledges a stipend from the Chinese Scholarship Council (CSC). C.M. acknowledges funding by the European Commission through a Marie Skłodowska Curie Individual Fellowship (703387). C.K. acknowledges support from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2017R1A6A3A03012331).Organic light‐emitting diodes (OLEDs) can emit light over much larger areas than their inorganic counterparts, offer mechanical flexibility, and can be readily integrated on various substrates and backplanes. However, the amount of light they emit per unit area is typically lower and the required operating voltage is higher, which can be a limitation for emerging applications of OLEDs, e.g., in outdoor and high‐dynamic‐range displays, biomedical devices, or visible‐light communication. Here, high‐luminance, blue‐emitting (λpeak = 464 nm), fluorescent p–i–n OLEDs are developed by combining three strategies: First, the thickness of the intrinsic layers in the device is decreased to reduce internal voltage loss. Second, different electron‐blocking layer materials are tested to recover efficiency losses resulting from this thickness reduction. Third, the geometry of the anode contact is optimized, which leads to a substantial reduction in the in‐plane resistive voltage losses. The OLEDs retain a maximum external quantum efficiency of 4.4% as expected for an optimized fluorescent device and reach a luminance of 132 000 cd m−2 and an optical power density of 2.4 mW mm−2 at 5 V, a nearly eightfold improvement compared to the original reference device.PostprintPeer reviewe

New technologies for site selection and evaluation of salt-cavern underground gas storages

In order to meet the demand of constructing salt-cavern underground gas storages (UGSs) in favorable salt mines for the regions that are neither major oil and gas production zones nor major natural gas consumer markets in South China, and solve the problems of unclear conditions for selecting salt-cavern gas storage sites and of inconsistent content and depth in evaluating gas storage conditions, based on investigation and analysis of salt-cavern UGS data in China and other countries, we proposed the principles of selecting gas storage sites in combination with geology and ground surface conditions, and developed a set of technologies in evaluating construction conditions for salt-cavern gas storages. By applying the selection principles of salt-cavern UGSs, we selected and sorted some salt mines in the three major natural gas consumer markets (the Yangtze River Delta, Central–South China, and Southeast Coast of China), and evaluated the conditions of constructing a gas storage in the Huai'an salt mine with better conditions. The following findings were obtained. First, the principles of selecting gas storage sites can be applied to quickly optimize and sort the selected targets, including 6 items of geological factors such as structure, burial depth, salt-bearing layer thickness, NaCl content, top rock, and reserves, and 3 other items such as ground surface conditions, water source and brine, distance from pipeline networks. Second, the evaluation system of UGS construction conditions integrates features of structure and salt-bearing strata, tightness, firmness, dissolubility evaluation, prediction of gas storage scale, and analysis of cavity making condition. In conclusion, the new evaluation technologies can not only effectively guide the site selection and evaluation of salt-cavern UGSs but provide foundation and power support for their scheme designs, and the presented pilot proposal for utilizing thick interlayers has achieved a perfect on-site application effect. This study is of great significance for constructing UGSs in China. Keywords: Salt-cavern, Underground gas storage, Site selection, Storage construction conditions, Strata feature, Appraisal system, Case analysis, Huai'an salt mine (Jiangsu

Protective Effect of Tang Wang One Decoction on the Retinal Vessels of Diabetic Rats

Objective. This study aimed to determine the influence of Tang Wang One Decoction (TWOD) on the retinal vessels of diabetic rats. Methods. The hemorheology of diabetic rats was observed. Morphological studies of retinal vessels were conducted using optical microscopy and electron microscopy. Immunological histochemistry assay was used to measure the expression levels of MMP-9, occludin, and claudin-5. Results. Obvious pathological damage was observed in the retinal vessels of diabetic rats. TWOD positively affected the hemorheology and morphology of retinal vessels. The decoction also decreased the expression of MMP-9 and increased the expression of occludin and claudin-5. Conclusions. The results suggest that the retinal protective effects of TWOD might be related to downregulation of MMP-9 and upregulation of occludin and claudin-5

Development of very high luminance p–i–n junction-based blue fluorescent organic light-emitting diodes

Organic light‐emitting diodes (OLEDs) can emit light over much larger areas than their inorganic counterparts, offer mechanical flexibility, and can be readily integrated on various substrates and backplanes. However, the amount of light they emit per unit area is typically lower and the required operating voltage is higher, which can be a limitation for emerging applications of OLEDs, e.g., in outdoor and high‐dynamic‐range displays, biomedical devices, or visible‐light communication. Here, high‐luminance, blue‐emitting (λpeak = 464 nm), fluorescent p–i–n OLEDs are developed by combining three strategies: First, the thickness of the intrinsic layers in the device is decreased to reduce internal voltage loss. Second, different electron‐blocking layer materials are tested to recover efficiency losses resulting from this thickness reduction. Third, the geometry of the anode contact is optimized, which leads to a substantial reduction in the in‐plane resistive voltage losses. The OLEDs retain a maximum external quantum efficiency of 4.4% as expected for an optimized fluorescent device and reach a luminance of 132 000 cd m−2 and an optical power density of 2.4 mW mm−2 at 5 V, a nearly eightfold improvement compared to the original reference device

Clinical Efficacy Observation of Acupuncture Treatment for Nonarteritic Anterior Ischemic Optic Neuropathy

Objective. To determine whether acupuncture treatment impacts the clinical efficacy of degenerative damage of the optic nerve caused by nonarteritic anterior ischemic optic neuropathy (NAION). Methods. 69 patients (93 eyes) with NAION who had been treated by acupuncture which is performed on different acupoints related to eyes by vertical insertion or Fingernail-pressure needle insertion. The best corrected visual acuity, mean defect (MD) and mean light sensitivity (MS) of the visual field, and latency and amplitude of pattern visual evoked potential (P-VEP) were compared before and after treatment. Results. After 2, 4, and 8 weeks of treatment, the total effective rates of visual acuity improvement were 74.19%, 78.89%, and 81.71%, respectively, and the decreased MD and increased MS were both statistically significant (P < 0.01). When compared with the situation before treatment, the average latency of the P100 wave was significantly reduced (P < 0.05), and the average amplitude was improved with no statistically significant difference (P > 0.05). Conclusions. Acupuncture treatment could obviously improve the visual function of patients with NAION and be used as complementary and alternative therapy in clinic

RNA-binding protein CELF6 modulates transcription and splicing levels of genes associated with tumorigenesis in lung cancer A549 cells

CELF6 (CUGBP Elav-Like Family Member 6), a canonical RNA binding protein (RBP), plays important roles in post-transcriptional regulation of pre-mRNAs. However, the underlying mechanism of lower expressed CELF6 in lung cancer tissues is still unclear. In this study, we increased CELF6 manually in lung cancer cell line (A549) and utilized transcriptome sequencing (RNA-seq) technology to screen out differentially expressed genes (DEGs) and alternative splicing events (ASEs) after CELF6 over-expression (CELF6-OE). We found that CELF6-OE induced 417 up-regulated and 1,351 down-regulated DEGs. Functional analysis of down-regulated DEGs showed that they were highly enriched in immune/inflammation response- related pathways and cell adhesion molecules (CAMs). We also found that CELF6 inhibited the expression of many immune-related genes, including TNFSF10, CCL5, JUNB, BIRC3, MLKL, PIK3R2, CCL20, STAT1, MYD88, and CFS1, which mainly promote tumorigenesis in lung cancer. The dysregulated DEGs were also validated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) experiment. In addition, CELF6 regulates the splicing pattern of large number of genes that are enriched in p53 signaling pathway and apoptosis, including TP53 and CD44. In summary, we made an extensive analysis of the transcriptome profile of gene expression and alternative splicing by CELF6-OE, providing a global understanding of the target genes and underlying regulation mechanisms mediated by CELF6 in the pathogenesis and development of lung cancer