Coupling Efficiency Measurements for Long-pulsed Solid Sodium Laser Based on Measured Sodium Profile Data

In 2013, a serial sky test has been held on 1.8 meter telescope in Yunnan observation site after 2011-2012 Laser guide star photon return test. In this test, the long-pulsed sodium laser and the launch telescope have been upgraded, a smaller and brighter beacon has been observed. During the test, a sodium column density lidar and atmospheric coherence length measurement equipment were working at the same time. The coupling efficiency test result with the sky test layout, data processing, sodium beacon spot size analysis, sodium profile data will be presented in this paper

Multifunctional polyimides for resistive switching memory devices based on flexible transparent polyimide–silver nanowires hybrid electrodes

Abstract With the quick development of flexible memory electronics, multifunctional organic materials have been the necessary for fabricating electronics. In this work, the highly transparent and flexible electrode was successfully prepared by coating the high‐performance silver nanowires (AgNWs) onto the colorless polyimide (PI) substrate. The prepared flexible PI–AgNWs electrodes exhibited a relatively low sheet resistance of 15 Ω/sq with the high transparency of 68% at the wavelength of 400 nm. A novel kind of polyimide TPC6FPI was successfully synthesized and characterized with the excellent thermostability and high glass transition temperature (Tg) above 250°C. Furthermore, a kind of flexible transparent PI–AgNWs/TPC6FPI/Al resistive memory device was prepared and exhibited good SRAM switching behavior with the threshold voltage of around 2.1 V and the ON/OFF current ratio of ˜104, which indicated that multifunctional PI‐based memory device showed the potential to the wearable devices

Ultrastable Tb-organic framework as a selective sensor of phenylglyoxylic acid in urine

Industrial pollution and harmful chemicals seriously affect environment and human health. Styrene is a common air toxicant with widespread exposure sources, including smoking, automobile exhaust, and plastic pollutants. Phenylglyoxylic acid (PGA) is a typical biomarker for exposed styrene. Therefore, it is crucial to quickly identify and quantitatively detect PGA. Herein, an ultrastable terbium metal-organic framework (Tb-MOF 1) was developed, and the luminescence film (1/PLA) consisting of polylactic acid (PLA) and 1 was fabricated as a sensor for rapid detection of PGA. The sensor possesses the advantages of efficient detection [limit of detection (LOD) is 1.05 × 10-4 mg/mL] and rapid response speed (less than 10 s) for PGA in urine. Furthermore, this sensor exhibits high stability, outstanding anti-interference ability, and excellent recyclability. Based on this film technology, a paper-based probe was then developed for portable and convenient detection. The probe could easily distinguish different concentrations of PGA under the naked eye toward practical sensing applications. Meanwhile, photoinduced electron transfer was demonstrated to be responsible for the luminescence sensing. Hence, this study indicates that Tb-MOF is a promising material to detect PGA for evaluating the effect of styrene on the body.Ministry of Education (MOE)This work was financially supported by the NSFC (21875025), the Program of Chongqing Science and Technology Commission (cstc2018jcyjAX0296), the Innovation Research Group at Institutions of Higher Education in Chongqing (CXQT19027), and the Science and Technology Research Program of Chongqing Municipal Education Commission (KJZD-K201801101). The research was also supported by the Ministry of Education Singapore under the Academic Research Funds (RT12/19 and MOE-MOET2EP10120-0003)

Excitation‐Dependent Long‐Life Luminescent Polymeric Systems under Ambient Conditions

Organic room temperature luminescent materials present a unique phosphorescence emission with a long lifetime. However, many of these materials only emit single blue or green color in spite of external stimulation, and their color tunability is limited. Herein, we report a rational design to extend the emission color range from blue to red by controlling the doping of simple pyrene derivatives into a robust polymer matrix. The integration of these pyrene molecules into the polymer films enhances the intersystem crossing pathway, decreases the first triplet level of the system, and ensures the films show a sensitive response to excitation energy, finally yielding excitation-dependent long-life luminescent polymeric systems under ambient conditions. These materials were used to construct anti-counterfeiting patterns with multicolor interconversion, presenting a promising application potential in the field of information security.Agency for Science, Technology and Research (A*STAR)Accepted versionThis work was financially supported by the National Natural Science Foundation of China (21875025), the special program of Chongqing Science and Technology Commission (cstc2018jcyjAX0296 and cstc2017zdcyzdyfX0007), Innovation Research Group at Institutions of Higher Education in Chongqing (CXQT19027), and the Science and Technology Research Program of Chongqing Municipal Education Commission (KJZD-K201801101 and KJ1709222). The research was also supported by the Singapore Agency for Science, Technology and Research (A*STAR) AME IRG grant (A1883c0005)

Novel Airflow-Field-Driven Melt Spinning 3D Printing of Tubular Scaffolds Based on Polycaprolactone Blends

The fabrication of various 3D tissue engineering tubular scaffolds with fibrous structures, to assist the human body in rapidly repairing a variety of ailments, is receiving more and more attention. Due to the inefficiency of the majority of fibrous preparation techniques, the question of how to rapidly produce the requisite three-dimensional tubular microfiber scaffold structures has become an urgent problem. In this study, an efficient polymer fiber preparation method was developed, using a high-speed airflow drive. Melt blending of polycaprolactone (PCL), polylactic acid (PLA), and tributyl citrate (TBC), was used for the printing material, to achieve the efficient preparation of tubular microfiber scaffolds with different structures. The scaffold diameter was as small as 2 mm, the wall thickness was up to 100 μm, and the fiber injection efficiency reached 15.48 g/h. By utilizing simulations to optimize the printing parameters and by adjusting the printing settings, it was possible to achieve a controlled fiber diameter in the range of 3 μm to 15 μm. In addition, plasma treatment was applied to the microfibers’ surface, to increase their wettability, and the efficiency of the hydrophilic modification was demonstrated. Furthermore, the mechanical property test demonstrated that the fibers have a tensile strength of 1.36 ± 0.16 MPa and a tensile strain of 30.8 ± 3.5%. The radial compressive strain of the tubular scaffold could reach 60% of the original scaffold’s diameter. Finally, the in vitro degradation of the fibers at various pH values was tested. The results showed that, under alkaline conditions, the surface of the fibers would be severely crushed and the rate of deterioration would increase

Effect of carbazolyl groups on photophysical properties of cyanuric chloride

Long-lived room temperature organic phosphorescence is highly useful in biological imaging, electroluminescent devices, information security, and security protection on account of its unique photophysical process and long-lived luminescence. In recent years, pure organic phosphorescent materials that do not contain rare precious metals have received increasing attention. Carbazole and its derivatives have been used to develop room temperature organic phosphorescent materials. However, the effect of carbazolyl groups on the photophysical properties of pure organic phosphors has rarely been reported. In this work, three cyanuric chloride phosphors (CzDCIT, BiCzDT, and TCzT) modified with different numbers of carbazolyl groups were synthesized. Several characterization techniques were employed to reveal distinct crystal forms of CzDCIT, BiCzDT, and TCzT. The single crystal diffraction of CzDCIT and BiCzDT showed not only different crystal packing modes, but also the formation of internal Haggregation. These three phosphor powders exhibited dual emissions of blue fluorescence and yellow phosphorescence at room temperature, with luminescence lifetimes of 0.16−0.34 s. Theoretical calculations indicated that different numbers of effective intersystem crossing channels between CzDCIT, BiCzDT, or TCzT were responsible for the luminescence lifetimes. After doping the phosphors into the polymer matrix, they exhibited good persistent phosphorescence and high recoverability in multiple compression-grinding cycles.ASTAR (Agency for Sci., Tech. and Research, S’pore)Accepted versio

Transformer-based biomarker prediction from colorectal cancer histology:A large-scale multicentric study

Deep learning (DL) can accelerate the prediction of prognostic biomarkers from routine pathology slides in colorectal cancer (CRC). However, current approaches rely on convolutional neural networks (CNNs) and have mostly been validated on small patient cohorts. Here, we develop a new transformer-based pipeline for end-to-end biomarker prediction from pathology slides by combining a pre-trained transformer encoder with a transformer network for patch aggregation. Our transformer-based approach substantially improves the performance, generalizability, data efficiency, and interpretability as compared with current state-of-the-art algorithms. After training and evaluating on a large multicenter cohort of over 13,000 patients from 16 colorectal cancer cohorts, we achieve a sensitivity of 0.99 with a negative predictive value of over 0.99 for prediction of microsatellite instability (MSI) on surgical resection specimens. We demonstrate that resection specimen-only training reaches clinical-grade performance on endoscopic biopsy tissue, solving a long-standing diagnostic problem