Molecular Packing Topology and Interactions to Decipher Mechanical Compliances in Dicyano-Distyrylbenzene Derivatives.

Flexible optoelectronics is the need of the hour as the market moves toward wearable and conformable devices. Crystalline π-conjugated materials offer high performance as active materials compared to their amorphous counterpart, but they are typically brittle. This poses a significant challenge that needs to be overcome to unfold their potential in optoelectronic devices. Unveiling the molecular packing topology and identifying interaction descriptors that can accommodate strain offers essential guiding principles for developing conjugated materials as active components in flexible optoelectronics. The molecular packing and interaction topology of eight crystal systems of dicyano-distyrylbenzene derivatives are investigated. Face-to-face π-stacks in an inclined orientation relative to the bending surface can accommodate expansion and compression with minimal molecular motion from their equilibrium positions. This configuration exhibits good compliance towards mechanical strain, while a similar structure with a criss-cross arrangement capable of distributing applied strain equally in opposite directions enhances the flexibility. Molecular arrangements that cannot reversibly undergo expansion and compression exhibit brittleness. In the isometric CT crystals, the disproportionate strength of the interactions along the bending plane and orthogonal directions makes these materials sustain a moderate bending strain. These results provide an updated explanation for the elastic bending in semiconducting π-conjugated crystals.

SURF: Direction-Optimizing Breadth-First Search Using Workload State on GPUs.

Graph data structures have been used in a wide range of applications including scientific and social network applications. Engineers and scientists analyze graph data to discover knowledge and insights by using various graph algorithms. A breadth-first search (BFS) is one of the fundamental building blocks of complex graph algorithms and its implementation is included in graph libraries for large-scale graph processing. In this paper, we propose a novel direction selection method, SURF (Selecting directions Upon Recent workload of Frontiers) to enhance the performance of BFS on GPU. A direction optimization that selects the proper traversal direction of a BFS execution between the push and pull phases is crucial to the performance as well as for efficient handling of the varying workloads of the frontiers. However, existing works select the direction using condition statements based on predefined thresholds without considering the changing workload state. To solve this drawback, we define several metrics that describe the state of the workload and analyze their impact on the BFS performance. To show that SURF selects the appropriate direction, we implement the direction selection method with a deep neural network model that adopts those metrics as the input features. Experimental results indicate that SURF achieves a higher direction prediction accuracy and reduced execution time in comparison with existing state-of-the-art methods that support a direction-optimizing BFS. SURF yields up to a 5.62× and 3.15× speedup over the state-of-the-art graph processing frameworks Gunrock and Enterprise, respectively.

Mitigating Cold Start Problem in Serverless Computing with Function Fusion.

As Artificial Intelligence (AI) is becoming ubiquitous in many applications, serverless computing is also emerging as a building block for developing cloud-based AI services. Serverless computing has received much interest because of its simplicity, scalability, and resource efficiency. However, due to the trade-off with resource efficiency, serverless computing suffers from the cold start problem, that is, a latency between a request arrival and function execution. The cold start problem significantly influences the overall response time of workflow that consists of functions because the cold start may occur in every function within the workflow. Function fusion can be one of the solutions to mitigate the cold start latency of a workflow. If two functions are fused into a single function, the cold start of the second function is removed; however, if parallel functions are fused, the workflow response time can be increased because the parallel functions run sequentially even if the cold start latency is reduced. This study presents an approach to mitigate the cold start latency of a workflow using function fusion while considering a parallel run. First, we identify three latencies that affect response time, present a workflow response time model considering the latency, and efficiently find a fusion solution that can optimize the response time on the cold start. Our method shows a response time of 28-86% of the response time of the original workflow in five workflows.

Excited-state non-radiative decay in stilbenoid compounds: an ab initio quantum-chemistry study on size and substituent effects.

In the framework of optoelectronic luminescent materials, non-radiative decay mechanisms are relevant to interpret efficiency losses. These radiationless processes are herein studied theoretically for a series of stilbenoid derivatives, including distyrylbenzene (DSB) and cyano-substituted distyrylbenzene (DCS) molecules in vacuo. Given the difficulties of excited-state reaction path determinations, a simplified computational strategy is defined based on the exploration of the potential energy surfaces (PES) along the elongation, twisting, and pyramidalization of the vinyl bonds. For such exploration, density functional theory (DFT), time-dependent (TD)DFT, and complete-active-space self-consistent field/complete-active-space second-order perturbation theory (CASSCF/CASPT2) are combined. The strategy is firstly benchmarked for ethene, styrene, and stilbene; next it is applied to DSB and representative DCS molecules. Two energy descriptors are derived from the approximated PES, the Franck-Condon energy and the energy gap at the elongated, twisted, and pyramidalized structures. These energy descriptors correlate fairly well with the non-radiative decay rates, which validates our computational strategy. Ultimately, this strategy may be applied to predict the luminescence behavior in related compounds.

MGEScan: a Galaxy-based system for identifying retrotransposons in genomes.

UNLABELLED: : MGEScan-long terminal repeat (LTR) and MGEScan-non-LTR are successfully used programs for identifying LTRs and non-LTR retrotransposons in eukaryotic genome sequences. However, these programs are not supported by easy-to-use interfaces nor well suited for data visualization in general data formats. Here, we present MGEScan, a user-friendly system that combines these two programs with a Galaxy workflow system accelerated with MPI and Python threading on compute clusters. MGEScan and Galaxy empower researchers to identify transposable elements in a graphical user interface with ready-to-use workflows. MGEScan also visualizes the custom annotation tracks for mobile genetic elements in public genome browsers. A maximum speed-up of 3.26× is attained for execution time using concurrent processing and MPI on four virtual cores. MGEScan provides four operational modes: as a command line tool, as a Galaxy Toolshed, on a Galaxy-based web server, and on a virtual cluster on the Amazon cloud. AVAILABILITY AND IMPLEMENTATION: MGEScan tutorials and source code are available at http://mgescan.readthedocs.org/ CONTACT: hatang@indiana.edu or syoh@ajou.ac.kr SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Electrofluorochromic Hydrogels by Oligothiophene-Based Color-Tunable Fluorescent Dye Doping.

Soft electronic materials hold great promise for advancing flexible functional devices. Among the various soft materials available, hydrogels are particularly attractive for soft electronic device development due to their inherent properties, including transparency, shape adaptability through swelling/deswelling, and self-healing capabilities. Transparent hydrogels contribute to the creation of advanced smart devices such as sensors, smart windows, and anticounterfeiting technologies. Poly(vinyl alcohol) hydrogels are used as a platform for creating electrofluorochromic (EFC) devices in combination with oligothiophene-conjugated benzothiazole derivatives (OCBs) as fluorescent emitters. OCBs demonstrated excited-state intramolecular proton transfer (ESIPT) behavior with a large Stokes shift and emission changes responsive to solvent polarity and pH stimuli. Even in the solid state, OCBs exhibited strong fluorescence emission across a wide range of colors from blue to red, making them exceptionally well-suited for EFC device development. Their quantum yields in the powder state were obtained between 2.3% and 19.9%. Through the incorporation of OCBs into a PVA hydrogel (OCB@PVA), we achieved the successful fabrication of flexible EFC devices, including electronic paper and smart panels. When electric potentials (-2.4 and +2.4 V) were applied in OCB@PVA, fluorescence color changes were observed by an electrochemically induced pH change owing to electrohydrolysis of water. These devices demonstrated the potential of OCB@PVA hydrogels in the realm of flexible electronics. They could be used to create innovative and versatile devices with stimuli-responsive fluorescence properties.

Comprehensive treatment protocol for peri-implantitis: an up-to date narrative review of the literature.

This narrative review describes up-to-date treatment options for peri-implantitis and proposes a treatment protocol and flowchart based on the current scientific evidence. Peri-implantitis treatment should be based on the phased treatment protocol for periodontitis, which is a continuous flow of decisions for extraction, nonsurgical and surgical treatments with step-by-step re-evaluation. The protocol's goals are to fulfill the success criteria for peri-implantitis treatment (probing depth of ≤5 mm, and absence of bleeding on probing, suppuration, and progressive bone loss) and to halt disease progression. Fixtures with peri-implantitis can initially be classified as failed or failing. A failed implant needs to be removed. In contrast, nonsurgical and surgical treatments can be applied to a failing implant. Nonsurgical treatment should be the initial treatment for failing implants; however, sole nonsurgical treatment was regarded as inefficient for peri-implantitis. Recent studies have found that the adjunctive use of antibiotics to nonsurgical debridement increased the success of nonsurgical treatment for peri-implantitis. Surgical treatments can be classified into resective, access, and reconstructive surgeries. The technique should be selected according to the patient's bone defect configuration, which relate to regenerative potential. Various combinations of decontamination methods (e.g., mechanical, chemical, and pharmacological approaches) are required to achieve absolute surface decontamination. Clinicians should select an appropriate surface decontamination strategy according to the purpose of surgery. After signs of disease disappear and its progression is halted through active peri-implantitis treatment, it is necessary to enroll patients into maintenance programs. Compliance of patients with the maintenance program reduces the recurrence of peri-implantitis and sustains clinical success after treatment. Maintenance visits should include professional plaque control and hygiene care reinforcement for patients, and their interval should be set according to individual peri-implantitis risk. Clinicians should remind that peri-implantitis treatment is not a single procedure, but rather a continuing cycle of treatment and re-evaluation.

Structural and Electronic Origin of Bis-Lactam-Based High-Performance Organic Thin-Film Transistors.

We describe herein the comprehensive theoretical and experimental studies on the transistor mobility of organic semiconductors by correlating a two-dimensional (2D) intermolecular interaction with thin-film morphology and the electronic coupling structure. We developed a novel bis-lactam-based small molecule, 1,5-dioctyl-3,7-di(thiophen-2-yl)-1,5-naphthyridine-2,6-dione (C8-NTDT), with a 2D-type C-H···O═C intermolecular interaction along the in-plane directions of the crystal packing structure, which is characteristically different from the one-dimensional-type intermolecular interaction shown in the typical bis-lactam molecule of 2,5-dioctyl-3,6-di(thiophen-2-yl)pyrrolo[3,4- c]pyrrole-1,4-dione (C8-DPPT). Experimentally and theoretically, C8-NTDT exhibited more favorable thin-film morphology and an electronic coupling structure for charge transport because of its unique 2D intermolecular interactions compared with C8-DPPT. In fact, C8-NTDT exhibited a hole mobility of up to 1.29 cm2 V-1 s-1 and an on/off ratio of 107 in a vacuum-processed device. Moreover, the high solubility with the 2D electronic coupling structure of C8-NTDT enables versatile solution processing for device fabrication without performance degradation compared to the vacuum-processed device. As an example, we could demonstrate a hole mobility of up to 1.10 cm2 V-1 s-1 for the spin-coated devices, which is one of the best performances among the solution-processed organic field-effect transistors based on bis-lactam-containing small molecules.

Highly Luminescent 2D-Type Slab Crystals Based on a Molecular Charge-Transfer Complex as Promising Organic Light-Emitting Transistor Materials.

A new 2:1 donor (D):acceptor (A) mixed-stacked charge-transfer (CT) cocrystal comprising isometrically structured dicyanodistyrylbenzene-based D and A molecules is designed and synthesized. Uniform 2D-type morphology is manifested by the exquisite interplay of intermolecular interactions. In addition to its appealing structural features, unique optoelectronic properties are unveiled. Exceptionally high photoluminescence quantum yield (ΦF ≈ 60%) is realized by non-negligible oscillator strength of the S1 transition, and rigidified 2D-type structure. Moreover, this luminescent 2D-type CT crystal exhibits balanced ambipolar transport (µh and µe of ≈10-4 cm2 V-1 s-1 ). As a consequence of such unique optoelectronic characteristics, the first CT electroluminescence is demonstrated in a single active-layered organic light-emitting transistor (OLET) device. The external quantum efficiency of this OLET is as high as 1.5% to suggest a promising potential of luminescent mixed-stacked CT cocrystals in OLET applications.

Patterned Taping: A High-Efficiency Soft Lithographic Method for Universal Thin Film Patterning.

As a universal lithographic technique for microscale/nanoscale film patterns, we develop a strategy for the use of soft lithographically patterned pressure-sensitive tape (patterned tape) as a pattern-transporting stamp material. Patterning was successfully implemented through the selective detachment and/or attachment of various thin films, including organic and metallic layers demanding no subsequent physical, thermal, or chemical treatment, as this incurs the risk of the deformation of the thin film and the deterioration of its functionalities. Its features of universal adhesion and flexibility enable pressure-sensitive tapes to form patterns on a variety of surfaces: organic, polymeric, and inorganic surfaces as well as flat, curved, uneven, and flexible substrates. Moreover, the proposed technique boasts the unique and distinct advantages of short operation time, supreme patterning yield, and multilayer stacking capability, which suggest considerable potential for their application to advanced optoelectronic device fabrication.

Characterization of microbial associations in human oral microbiome.

Microorganisms interact with each other within a community. Within the same community, some microorganisms tend to co-exist, whereas some others tend to avoid each other. The association among microorganisms can be revealed by computing the correlation between their abundance patterns that are measured through metagenomic sequencing across multiple communities. In this paper, we built an association network among microorganisms from the human oral microbiome. To improve its accuracy, we adopted a network deconvolution algorithm to filter out indirect associations, and we used an ensemble of three correlation measures to filter out the false-positive associations. When applying on the metagenomic data from human oral samples, experimental results showed that phylogenetically close microorganisms formed highly correlated network clusters. Additionally, most of the identified mutually exclusive associations were related to the order Lactobacillales.

Ensemble learning with active example selection for imbalanced biomedical data classification.

In biomedical data, the imbalanced data problem occurs frequently and causes poor prediction performance for minority classes. It is because the trained classifiers are mostly derived from the majority class. In this paper, we describe an ensemble learning method combined with active example selection to resolve the imbalanced data problem. Our method consists of three key components: 1) an active example selection algorithm to choose informative examples for training the classifier, 2) an ensemble learning method to combine variations of classifiers derived by active example selection, and 3) an incremental learning scheme to speed up the iterative training procedure for active example selection. We evaluate the method on six real-world imbalanced data sets in biomedical domains, showing that the proposed method outperforms both the random under sampling and the ensemble with under sampling methods. Compared to other approaches to solving the imbalanced data problem, our method excels by 0.03-0.15 points in AUC measure.