•FDM 3D printing of carbon nanotube/thermoplastic polyurethane nanocomposite.•Monolithic manufacturing process of multiaxial force sensors (Fx, Fy, and Fz).•3D cross cubic structure is proposed for ...multiaxial force sensing.•High sensitivity to small forces by using a piezoresistivity.
We developed a new method to directly fabricate 3D multiaxial force sensor using fused deposition modeling (FDM) 3D printing of functionalized nanocomposite filaments. Here, 3D cubic cross shaped force sensor is suggested to measure the forces from three axes (x, y and z). The sensor has two components – a structural part and a sensing part – both of which are concurrently fabricated by 3D printing with different functional filaments. The structural part is printed with thermoplastic polyurethane (TPU) filament and the sensing part is printed with carbon nanotube (CNT)/TPU nanocomposite filament with a piezoresistivity on the surface of the structural part. The resistances of the sensing part are measured in three axial directions; Rx, Ry, and Rz and the force applied on each axis is measured by the resistance change. The 3D-printed multiaxial force sensor could detect the sub-millimeter scale deflection and its corresponding force on each axis. According to the sensing principle, when Fz=4N was applied, Rz was decreased by 2% while only 0.2% resistance change of Ry was induced. In addition, a simultaneous resistance measurement system was developed for a real-time force sensing in three axes. With its customizability, rapid manufacturing, and economic feasibility, this manufacturing approach allows direct fabrication of multiaxial sensors without additional assembly or integration processes.
Optimization and analysis of conjugated polymer side chains for high‐performance organic photovoltaic cells (OPVs) reveal a critical relationship between the chemical structure of the side chains and ...photovoltaic properties of polymer‐based bulk heterojunction OPVs. In particular, the impact of the alkyl side chain length on the π‐bridging (thienothiophene, TT) unit is considered by designing and synthesizing a series of benzodithiophene derivatives (BDT(T)) and thieno3,2‐bthiophene‐π‐bridged thieno3,4‐cpyrrole‐4,6(5H)‐dione (ttTPD) alternating copolymers, PBDT(T)‐(R2)ttTPD, with alkyl chains of varying length on the TT unit. Using a combination of 2D X‐ray diffraction, Raman spectroscopy, and electrical device characterization, it is elucidated in detail how these subtle changes to the chemical structure affect the molecular conformation, thin film molecular packing, blend film morphology, optoelectronic properties, and hence overall photovoltaic performance. For copolymers employing both the alkoxy or alkylthienyl‐substituted BDT motifs, it is found that octyl side chains on TT unit yield the maximum degree of molecular backbone coplanarity and result in the highest quality of molecular packing and optimized hole mobility. Inverted devices fabricated using this PBDTT‐8ttTPD: polymer/6,6‐phenyl‐C71‐butylic acid methyl ester active layer show a maximum power conversion efficiency (PCE) of 8.7% with large area cells (0.64 cm2) maintaining a PCE of 7.5%.
Optimization and analysis of conjugated polymer side chains for high‐performance organic photovoltaic cells (OPVs) reveals a critical relationship between the chemical structure of the side chains and the photovoltaic properties of bulk heterojunction OPVs. In particular, the impact of the alkyl side chain length on the π‐bridging thienothiophene (TT) unit is considered, by designing and synthesizing a series of copolymers, PBDT(T)‐(R2)ttTPD.
Participating in the repair of nuclear DNA is one mechanism by which p53 suppresses tumorigenesis, but there is growing evidence that p53 also helps maintain the mitochondrial genome through its ...translocation into mitochondria and interactions with mtDNA repair proteins. Because of the susceptibility of mtDNA to oxidative damage and replication errors, it is vital to protect mtDNA genomic stability to preserve health and fitness. Here, we focus on reviewing the evidence for the involvement of p53 in maintaining the integrity of mtDNA through its activities in both the nucleus and the mitochondria.
This paper presents a linear-mode optical sensor for the feasible applications of unmanned vehicle LiDAR systems, in which a pulsed-erbium fiber laser is exploited as a light source and a 16-channel ...transimpedance amplifier (TIA) array is utilized in an optical Rx module with low-cost InGaAs PIN photodiodes. In particular, a voltage-mode CMOS feedforward (VCF-TIA) is newly proposed to achieve twice higher transimpedance gain with lower noise and similar bandwidth characteristics than a conventional inverter TIA, thereby enabling longer detection. Test chips of the 16-channel VCF-TIA array realized in a standard 0.18-μm CMOS process demonstrate 76.3-dBΩ transimpedance gain, 6.3-pA/sqrt(Hz) average noise current spectral density, less than -33-dB crosstalk between channels, and 29.8-mW power dissipation per channel from a single 1.8-V supply. Automatic gain control is also equipped to extend input dynamic range for near-range detection. Hence, the proposed linear-mode optical sensor clearly detects the reflected optical pulses from the target of 5% reflection rate within the range of 0.5-25 m.
Tumor-associated lymphatic vessels (LV) serve as a route of cancer dissemination through the prometastatic crosstalk between lymphatic endothelial cells (LECs) lining the LVs and cancer cells. ...Compared to blood endothelial cell-derived angiocrine factors, however, LEC-secreted factors in the tumor microenvironment and their roles in tumor metastasis are poorly understood. Here, we report that ELK3 expressed in LECs contributes to the dissemination of cancer cells during tumor growth by providing oncogenic miRNAs to tumor cells through exosomes. We found that conditioned medium from ELK3-suppressed LECs (LCM) lost its ability to promote the migration and invasion of breast cancer cells such as MDA-MB-231, Hs578T and BT20 in vitro. Suppression of ELK3 in LECs diminished the ability of LECs to promote tumor growth and metastasis of MDA-MB-231 in vivo. Exosomes derived from LECs significantly increased the migration and invasion of MDA-MB-231 in vitro, but ELK3 suppression significantly diminished the pro-oncogenic activity of exosomes from LECs. Based on the miRNA expression profiles of LECs and functional analysis, we identified miR-503-3p, miR-4269 and miR-30e-3p as downstream targets of ELK3 in LECs, which cause the above phenotype of cancer cells. These findings strongly suggest that ELK3 expressed in LECs is a major regulator that controls the communication between the tumor microenvironment and tumors to support cancer metastasis.
Inbound open innovation for purposive knowledge acquisition and generation is a viable strategy for new ventures to fill out internal knowledge gaps through external innovation networks. However, the ...smallness and newness liabilities to which the firms are subject can restrict their potential to take increased innovation returns of inbound-oriented activities. Against this practical issue, we test assumptions that employing interorganizational learning (IOL) is beneficial for ventures to achieve better inbound open innovation performance and that the performing-by-learning mechanism is contingent on their entrepreneurial posture for productive knowledge utilization, referring to entrepreneurial orientation (EO). Findings from an analysis of 218 inbound open innovation projects of ventures demonstrate that firms showing higher exploitative and exploratory IOL practices enjoy greater technological and business performance, corresponding to the value creation and capture of inbound open innovation. Furthermore, EO serves as a significant moderator to leverage the advantages of exploratory learning for technological performance and exploitative learning for business performance. This study contributes to the literature by adding original findings that the entrepreneurial mode of interactions at the external innovation networks is essential for ventures to orchestrate the distinctive yet reciprocal functions of exploitative and exploratory learning in capitalizing on network-available knowledge. In practice, institutionalizing the IOL–EO nexus in the firms’ inbound-oriented activities legitimizes the contingent rationality for increased innovation returns in technology and business.
•Inbound open innovation performance depends on interorganizational learning (IOL) and entrepreneurial orientation (EO).•The composite use of exploitative and explorative IOL practices is a prerequisite for higher performance.•EO of firms serves as an essential fertilizer to leverage different performance benefits of the IOL practices.•Instituting the IOL–EO nexus offers the contingent rationality for increased returns of inbound open innovation.
To apply a texture analysis of apparent diffusion coefficient (ADC) maps to evaluate glioma heterogeneity, which was correlated with tumor grade.
Forty patients with glioma (WHO grade II (n = 8), ...grade III (n = 10) and grade IV (n = 22)) underwent diffusion-weighted imaging (DWI), and the corresponding ADC maps were obtained. Regions of interest containing the lesions were drawn on every section of the ADC map containing the tumor, and volume-based data of the entire tumor were constructed. Texture and first order features including entropy, skewness and kurtosis were derived from the ADC map using in-house software. A histogram analysis of the ADC map was also performed. The texture and histogram parameters were compared between low-grade and high-grade gliomas using an unpaired student's t-test. Additionally, a one-way analysis of variance analysis with a post-hoc test was performed to compare the parameters of each grade.
Entropy was observed to be significantly higher in high-grade gliomas than low-grade tumors (6.861±0.539 vs. 6.261±0.412, P = 0.006). The fifth percentiles of the ADC cumulative histogram also showed a significant difference between high and low grade gliomas (836±235 vs. 1030±185, P = 0.037). Only entropy proved to be significantly different between grades III and IV (6.295±0.4963 vs. 7.119±0.3165, P<0.001). The diagnostic accuracy of ADC entropy was significantly higher than that of the fifth percentile of the ADC histogram (P = 0.0034) in distinguishing high- from low-grade glioma.
A texture analysis of the ADC map based on the entire tumor volume can be useful for evaluating glioma grade, which provides tumor heterogeneity.
In this study, monolayer hexagonal boron nitride (h‐BN) grown via chemical vapor deposition (CVD) as an effective electron blocking layer (EBL) for the organic photovoltaics (OPVs) is proposed. ...Unexpectedly, it is found that h‐BN can replace the commonly used hole transport layers (HTLs), i.e., molybdenum trioxide (MoO3) and poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) in an inverted device architecture. Here, a wet‐transfer technique is employed and a single layer of h‐BN on top of the PV2000:PC60BM blend is successfully placed. Analysis of the bandgap diagram shows that the monolayer h‐BN makes smaller barrier for holes but significantly larger barrier for electrons. This makes the h‐BN effective in blocking electrons while creating a possible path for the holes through tunneling to the electrode, due to the low energy barrier at the PV2000/h‐BN interface. Using h‐BN as an EBL, efficient inverted OPVs are achieved with an average solar‐to‐power conversion efficiency of 6.13%, which is comparable with that of reference devices based on MoO3 (7.3%) and PEDOT:PSS (7.6%) as HTLs. Interestingly, the devices with h‐BN shows great light‐soak stability. The study reveals that the monolayer h‐BN grown by CVD could be an effective alternative EBL for the fabrication of efficient, lightweight, and stable OPVs.
In this study, efficient inverted organic photovoltaics using hexagonal boron nitride as an electron blocking layer is fabricated and the device stability, as compared to the reference devices, is improved.
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