Sequential recommendation aims to leverage users' historical behaviors to predict their next interaction. Existing works have not yet addressed two main challenges in sequential recommendation. First, user behaviors in their rich historical sequences are often implicit and noisy preference signals, they cannot sufficiently reflect users' actual preferences. In addition, users' dynamic preferences often change rapidly over time, and hence it is difficult to capture user patterns in their historical sequences. In this work, we propose a graph neural network model called SURGE (short for SeqUential Recommendation with Graph neural nEtworks) to address these two issues. Specifically, SURGE integrates different types of preferences in long-term user behaviors into clusters in the graph by re-constructing loose item sequences into tight item-item interest graphs based on metric learning. This helps explicitly distinguish users' core interests, by forming dense clusters in the interest graph. Then, we perform cluster-aware and query-aware graph convolutional propagation and graph pooling on the constructed graph. It dynamically fuses and extracts users' current activated core interests from noisy user behavior sequences. We conduct extensive experiments on both public and proprietary industrial datasets. Experimental results demonstrate significant performance gains of our proposed method compared to state-of-the-art methods. Further studies on sequence length confirm that our method can model long behavioral sequences effectively and efficiently.

Atomic force microscopy (AFM) was used to characterize the surface damage (nanoindentations) effect on the chemical durability of glass surfaces (silica and soda-lime silicate glasses, WG). In basic solutions, an enhanced dissolution rate is reported and quantified at indentation sites (+10.5 nm/h and +52 nm/h for silica and WG, respectively) whereas none was observed once the indented surfaces were thermally annealed at 0.9 × T(g) for 2 h, a thermal treatment known for curing high pressure-induced permanent densification in oxides glasses. A direct link between high pressure-induced structural modifications encountered during nanoindentation and the measured dissolution rates is established. It is shown that this property conjointly used with the high resolution of the atomic force microscope may be used for probing, at the nanometer scale, the size and the nature of the structurally modified area underneath residual nanoindentation impressions. As an example, for 10 mN Vickers nanoindentations on WG, the zone affected by the permanently and structurally modified zone under the residual impression is found to be equal to (741 ± 30) nm with a transition zone thickness from the fully densified material to the elastically deformed one ranging between 115 and 165 nm.

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Arrhythmogenesis in acute myocardial infarction (MI) is associated with depolarization of resting membraine potential (RMP) and decrease of inward rectifier potassium current (IK1) in cardiomyocytes. However, clinical anti-arrhythmic agents that primarily act on RMP by enhancing the IK1 channel are not currently available. We hypothesized that zacopride, a selective and moderate agonist of the IK1/Kir2.1 channels, prevents and cures acute ischemic arrhythmias. To test this viewpoint, adult Sprague-Dawley (SD) rats were subjected to MI by ligating the left main coronary artery. The antiarrhythmic effects of zacopride (i.v. infusion) were observed in the settings of pre-treatment (zacopride given 3 min prior to coronary occlusion), post-treatment (zacopride given 3 min after coronary occlusion) and therapeutic treatment (zacopride given 30 s after the onset of the first sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) post MI). In all the three treatment modes, zacopride (15 μg/kg) inhibited MI-induced ventricular tachyarrhythmias, as shown by significant decreases in the premature ventricular contraction (PVC) and the duration and incidence of VT or VF. In Langendorff perfused rat hearts, the antiarrhythmic effect of 1 μmol/L zacopride were reversed by 1 μmol/L BaCl2, a blocker of IK1 channel. Patch clamp results in freshly isolated rat ventricular myocytes indicated that zacopride activated the IK1 channel and thereby reversed hypoxia-induced RMP depolarization and action potential duration (APD) prolongation. In addition, zacopride (1 μmol/L) suppressed hypoxia- or isoproterenol- induced delayed afterdepolarizations (DADs). In Kir2.x transfected Chinese hamster ovary (CHO) cells, zacopride activated the Kir2.1 homomeric channel but not the Kir2.2 or Kir2.3 channels. These results support our hypothesis that moderately enhancing IK1/Kir2.1 currents as by zacopride rescues ischemia- and hypoxia- induced RMP depolarization, and thereby prevents and cures acute ischemic arrhythmias. This study brings a new viewpoint to antiarrhythmic theories and provides a promising target for the treatment of acute ischemic arrhythmias.

Polymeric room temperature phosphorescence (RTP) materials have attracted tremendous attentions owing to their excellent flexibility, easy processing, low cost, and good thermal stability. In this work, an improved strategy is proposed for ultralong RTP polymeric materials through copolymerizing the phosphor monomer with D (donor)−A (acceptor) structure and another monomer with ultrastrong multiple hydrogen bonds. A series of copolymers (P1–P4) containing different ratios of carbazole‐dibenzofuran (CDF) and ureidopyrimidinone (UPy) segments are successfully prepared. The obtained copolymers show ultralong phosphorescence lifetimes between 1.70 and 2.16 s with afterglow duration time between 15 and 17 s. The multiple hydrogen bonds of UPy groups can promote extremely intermolecular and intramolecular interactions, which immobilize the phosphors to prevent nonradiative transitions. Especially, these interactions lead to the copolymers can be robustly resistant to high temperature and humidity. Flexible and foldable anti‐counterfeiting with high temperature and humidity resistant features are achieved, which would be applied in practical special environments.

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-A robust methodology is established to predict the critical bending radius of a flexible AMOLED. According to the methodology, the critical bending radius of display manufactured by the same process could be reduced from 7 mm to 4 mm by modulating the layer stack thickness.Keywords -flexible, neutral plane, stress, strain, simulation, AMOLED. DOI # 10.1002/jsid.443 Objective and backgroundRecently, there are many significant investments in the development of flexible display technology. Several flexible AMOLED products are already available in the display market. But, these products are only slightly curved and remain rigid, which are not as much different from the present glass-based portable device as one could anticipate from a flexible display. In order to realize flexible display applied to the rollable or foldable device of next generation, it is necessary to reduce the critical bending radius.The structure of a flexible AMOLED display can be divided into several parts: the flexible substrate, TFT backplane, OLED, and encapsulation layers. The AMOLED display contains functional brittle inorganic layers that have different purposes and could easily fail during bending. A number of literatures have pointed out that we can place the mechanically vulnerable components (TFT backplane and OLED) close to the zero-strain plane (the neutral plane) to improve the reliability and flexibility of flexible displays.1-4 But, the inorganic layers used for encapsulation layers would be far away from neutral plane and easily fail during bending.OLED materials are extremely sensitive to ambient water vapor and oxygen, which causes oxidation of cathode and results in the formation of black spots in electroluminescence. [5][6][7][8] Therefore, keeping the performance of encapsulation layers during bending is important. The most common technique of encapsulation for flexible AMOLED is the thin-film encapsulation (TFE) 9-12 that is fabricated by alternative stacks of inorganic and organic layers. In order to protect the TFE layer, we modulate the thickness of organic layers. In our structure configuration, we maintain the neutral plane located on TFT and OLED layers but change the thicknesses of organic layers. The inorganic layers in TFE component could get closer to the neutral plane and take lesser strain. Experiment and process flowA robust methodology consisting of a mechanical model of multi-films under bending loads and experiment of bending test is proposed to predict the critical bending radius of a flexible AMOLED display. Figure 1 shows the process flow. We apply this methodology in different layer stack structure configuration and try to reduce the critical bending radius.The flexible AMOLED interpreted below is fabricated by PI substrate with SiNx bottom barrier to perform the IGZO TFT process, then, deposit the OLED material and encapsulated by thin-film encapsulation (TFE) process. The TFE layer is made by stacks of SiNx layers and "organic coating for planarization (OCP)" layers, alternately. SiNx is dep...