Singlet fission of organic molecules has attracted recent attention owing to its potential advantages in organic photovoltaic and electroluminescence applications. Its microscopic mechanism however ...remains stymied. Large couplings from charge-transfer (CT) state mediation were invoked to explain the ultrafast singlet fission rate observed in crystalline polyacene, but its experimental confirmation is still lacking. The singlet fission and triplet fusion of amorphous rubrene were investigated with time-resolved photoluminescence spectroscopy at different temperatures to extract the rates of singlet fission, triplet fusion, and triplet hopping. On the basis of the Marcus electron-transfer model, the deduced electronic coupling constant of the singlet fission process was found to be larger than that of the triplet fusion process, indicating that the singlet fission process undertakes a CT-state-mediated channel while the triplet fission process assumes a direct channel. This study thus confers supporting evidence of the existence of the CT-state-mediated channel for singlet fission of rubrene and offers an experimental approach to study singlet fission dynamics.
Dysregulation of hormones is considered a risk factor for obesity‐mediated breast tumorigenesis; however, obesity is associated with poor outcomes among women diagnosed with triple‐negative breast ...cancer (TNBC), which is a hormone‐independent breast cancer subtype. Thus, identifying the driving force behind the obesity‐breast cancer relationship is an urgent need. Here it is identified that diet‐induced obesity (DIO) facilitates tumorigenesis of TNBC cells. Mechanistically, DIO induces a metabolic addiction to fatty acid oxidation (FAO), accompanied by coordinated activation of Yes‐associated protein (YAP) signaling. Specifically, YAP governs mitochondrial redox homeostasis via transcriptional regulation of antioxidant‐related enzymes, which renders tumor cells capable of extenuating FAO‐elicited mitochondrial oxidative stress. Moreover, adipocytes‐derived fatty acids are identified to be responsible for enhancing the FAO‐YAP axis and antioxidative capacity, and higher expression of an obesity signature in breast cancer patients is positively correlated with YAP signaling and antioxidant genes. The findings uncover the crucial role of YAP in dictating mitochondrial redox homeostasis for obesity‐mediated metabolic adaptation and breast tumor progression.
It is identified that Yes‐associated protein (YAP) governs mitochondria redox homeostasis through the regulation of antioxidant gene expressions in obesity‐associated breast cancer cells. Activation of YAP alleviates metabolic stress from fatty acid oxidation, resulting in decreased metabolic stress and the promotion of a survival advantage.
Highlights • MLN4924 elicit anti-cancer property in human urothelial carcinoma cells. • MLN4924 activates endoplasmic reticulum (ER) stress and other cell stress response. • MLN4924 exhibits efficacy ...to inhibit urothelial carcinoma in vivo. • These findings provide evidence for clinical trials of MLN4924 in treatment of bladder cancer.
In this article, an innovative offline deep imitation learning algorithm for optimal trajectory planning is proposed. While many state‐of‐the‐art works achieved optimal trajectory planning, their ...systems were stable or quasistable, and their approaches rarely optimized the system's initial conditions (ICs). Here, a new unstable dynamic system task called “internal sliding object stabilization control” is proposed, modeled, and solved by deep imitation learning. Given the system's ICs, the neural networks (NNs) can imitate the iterative linear quadratic regulator (iLQR), generate optimal trajectories, and compute faster. A proportional–integral–derivative (PID) controller is used to track the unstable trajectories. Leveraging on the gradients of NNs, it can optimize the system's ICs, avoid obstacles stepwise, and ensure the worst bounds of NNs for safety. Subsequently, thorough simulations are conducted, including comparing the iLQR and PID controllers in the task, optimizing the system's different ICs by gradient descent, and finding the worst bound of the performance by gradient ascent. Results show that the proposed algorithm achieves considerably improved performance. Finally, experiments are conducted with a real manipulator to compare the proposed structure with the original iLQR. Results indicate that the proposed algorithm resembles the iLQR well. Program code and experiment results are in https://github.com/DanielYamChen/ISOSC.git.
A deep imitation learning structure is proposed for optimal trajectory planning of an unstable dynamic system. Given the system's initial conditions, the neural networks (NNs) imitate the iterative linear quadratic regulator to generate near‐optimal trajectories. Leveraging on NN gradients, optimizing the system's initial conditions, avoiding obstacles, and finding the NN worst bounds are achieved in simulations, with empirical experiments conducted.
This paper presents a new coordination manipulation strategy for a custom-made dual-arm robot. With master and slave coordination infrastructure, both spatial relation and sense of touch are ...considered to hold an object stably. Given the known trajectory of the master arm, the slave arm fuses position and force commands by using the Kalman filter to yield optimal compensation amounts. The proposed strategy has been experimentally evaluated, and the results confirm that it was capable of dealing with fragile and flexible objects. In addition, the influence of the loop time of the digital controller on force control for this task was also investigated in mathematical and simulated ways. Furthermore, a series of experiments were designed to explore the effects that have influences on errors in force control. The main factors that affect force control error were analyzed.
Additional energy loss pathways which occur in blue electrophosphorescent devices via through‐space charge transfer (TSCT) states of bipolar hosts are identified for the first time in this study. ...Blue phosphorescent organic light‐emitting diodes (PhOLEDs) with maximum external quantum efficiency from 22.7 to 30.5% are fabricated using new bipolar derivatives of benzimidazole, linked through phenyl spacer with different number of tert‐butyl substituted carbazoles, as hosts. Applicability of the newly synthesized compounds as hosts for blue PhOLEDs is justified by their high triplet levels (2.94–2.98 eV), bipolar charge‐transporting properties with charge mobilities up to 2.34 × 10−3 cm2 V−1 s−1 at electric field of 2.7 × 105 V cm−1, and high ionization potentials (5.63–5.81 eV). Weak microsecond‐lived emission, which is attributed to TSCT, is detected for the developed bipolar hosts. The different efficiencies of the fabricated PhOLEDs are partly related to energy losses via TSCT states, the presence of which is detected for the developed donor–acceptor hosts in both solution and solid‐state. To prevent energy losses through TSCT in PhOLEDs, the excited state energy of emitter has to be lower than triplet levels of bipolar host. It also has to be lower than the TSCT energy level of bipolar host for the fabrication highly efficient PhOLEDs.
Blue phosphorescent organic light‐emitting diodes based on derivatives of benzimidazole and different number of tert‐butyl substituted carbazolyl groups having phenyl spacers show state‐of‐art performance with maximum external quantum efficiencies from 22.7 to 30.5%. Differences in the efficiency of the devices are attributed to energy loss pathways of the host via through‐space charge transfer.
Metastasis is a major cause of mortality in cancer patients. Invadopodia are considered to be crucial structures that allow cancer cells to penetrate across the extracellular matrix (ECM) by using ...matrix metalloproteinases (MMPs). Previously, we isolated a highly invasive A431-III subline from parental A431 cells by Boyden chamber assay. The A431-III cells possess higher invasive and migratory abilities, elevated levels of MMP-9 and an enhanced epithelial-mesenchymal transition (EMT) phenotype. In this study, we discovered that A431-III cells had an increased potential to form invadopodia and an improved capacity to degrade ECM compared with the original A431 cells. We also observed enhanced phosphorylation levels of cortactin and Src in A431-III cells; these phosphorylated proteins have been reported to be the main regulators of invadopodia formation. Flavonoids, almost ubiquitously distributed in food plants and plant food products, have been documented to exhibit anti-tumor properties. Therefore, it was of much interest to explore the effects of flavonoid antioxidants on the metastatic activity of A431-III cells. Exposure of A431-III cells to two potent dietary flavonoids, namely luteolin (Lu) and quercetin (Qu), caused inhibition of invadopodia formation and decrement in ECM degradation. We conclude that Lu and Qu attenuate the phosphorylation of cortactin and Src in A431-III cells. As a consequence, there ensues a disruption of invadopodia generation and the suppression of MMP secretion. These changes, in concert, bring about a reduction in metastasis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To evaluate the safety and the efficacy of a radiation-free 2-step tract dilation technique in totally ultrasound-guided percutaneous nephrolithotomy (PCNL).
From Oct 2018 to Mar 2020, we ...prospectively and consecutively enrolled 18 patients with 19 kidney units with urolithiasis. The nephrostomy tract was established by the following four steps: 1) ultrasound-guided renal puncture, 2) first-stage serial dilation to 16 Fr with Amplatz dilators, 3) check and adjustment of the partially dilated tract with a ureteroscope, 4) second-stage dilation with a 24-Fr balloon dilator.
The median age was 62.0 IQR 11.0 years, and 11 (61.1%) were male. The median stone size was 3.3 3.6 cm2, and stone laterality was almost equal over both sides. Successful tract establishment on the first attempt without fluoroscopy was achieved in 18 (94.7%) operations. The median tract establishment time was 10.4 4.9 mins, and the median operation time was 67.0 52.2 mins. The median hemoglobin drop was 1.0 1.1 g/dL, and none required blood transfusion. Three (15.8%) developed fever. Pleural injury occurred in two (10.5%) operations (both had supracostal puncture), and one required drainage with pigtail. Stone-free status was achieved in 15 (77.8%) operations at 3 months postoperatively.
Herein we present a radiation-free 2-step tract dilation technique, which is characterized by ureteroscopic check of the partially dilated tract in between the first dilation with serial fascial dilators and the second dilation with balloon. Our data suggest that it is a safe and effective method.
Esophageal neuroendocrine neoplasms (NEN) are extremely rare and little is known about their risk factors. To identify the potential risk factors, we evaluated whether the history of substance use, ...including alcohol, tobacco and areca nut consumption was associated with esophageal NEN. Forty‐one esophageal NEN patients diagnosed between 2002 and 2019 from 17 hospital in Taiwan were enrolled as the cases. Controls were participants who received complete esophagogastroduodenoscopy in an endoscopic cohort and 123 eligible controls were matched to 41 cases (3:1) on age and gender. Alcohol drinking and cigarette smoking significantly increased the risk of esophageal NEN, with about a fourfold risk increase in alcohol drinkers as well as cigarette smokers. Moreover, use of cigarette smoking and alcohol consumption in combination demonstrated the highest risk of esophageal NEN with the risk increasing up to 20 times compared with non‐users. Alcohol consumption and cigarette smoking significantly increase risk of esophageal NEN and both alcohol and cigarette users had the highest risk.
Quantum dots (QDs), with their exceptional optical properties, have emerged as promising candidates to replace traditional phosphors in lighting and display technologies. This study delves into the ...integration strategies of QDs within glass and polymer matrices to engineer advanced quantum dot color converters (QDCCs) at the industrial scale for practical applications. To achieve enhancements in the photostability and thermal stability of QDCCs, we explore two distinct approaches: the dispersion of QDs in a hydrophilic glass matrix via a sol-gel process and the incorporation of QDs into a non-polar acrylate monomer to formulate QD/polymer nanocomposites. This research further investigates the optical behaviors of these composites, focusing on their light-scattering and propagation mechanisms, which are critical for optimizing light extraction efficiency in QDCCs. Additional optical film and light-scattering particles can improve color conversion efficiency by ~140%. These advancements present a significant step forward in the development of high-performance, energy-efficient, QD-based lighting and display systems.
PDF
