High frequency impedance based fault location in distribution system with DGs

Distributed Generations (DGs) with power electronic devices and their control loops will cause distortion to the fault currents and result in errors for power frequency measurement based fault locations. This might jeopardize the distribution system fault restoration and reduce the grid resilience. The proposed method uses high frequency (up to 3kHz) fault information and short window measurement to avoid the influence of DG control loops. Applying the DG high frequency impedance model, faults can be accurately located by measuring the system high frequency line reactance. Assisted with the DG side recorded unsynchronized data, this method can be employed to distribution systems with multiple branches and laterals

Mirror: A Universal Framework for Various Information Extraction Tasks

Sharing knowledge between information extraction tasks has always been a challenge due to the diverse data formats and task variations. Meanwhile, this divergence leads to information waste and increases difficulties in building complex applications in real scenarios. Recent studies often formulate IE tasks as a triplet extraction problem. However, such a paradigm does not support multi-span and n-ary extraction, leading to weak versatility. To this end, we reorganize IE problems into unified multi-slot tuples and propose a universal framework for various IE tasks, namely Mirror. Specifically, we recast existing IE tasks as a multi-span cyclic graph extraction problem and devise a non-autoregressive graph decoding algorithm to extract all spans in a single step. It is worth noting that this graph structure is incredibly versatile, and it supports not only complex IE tasks, but also machine reading comprehension and classification tasks. We manually construct a corpus containing 57 datasets for model pretraining, and conduct experiments on 30 datasets across 8 downstream tasks. The experimental results demonstrate that our model has decent compatibility and outperforms or reaches competitive performance with SOTA systems under few-shot and zero-shot settings. The code, model weights, and pretraining corpus are available at https://github.com/Spico197/Mirror .Comment: Accepted to EMNLP23 main conferenc

High frequency impedance based fault location in distribution system with DGs

Distributed generations (DGs) in the distribution systems are connected into the buses using power electronic converters. During fault, it is challenging to provide a constant impedance model for DGs in the system frequency due to the variable converter control strategies. System frequency impedance measurement based fault locations can be influenced by the converters’ fault behaviour. This study addresses this problem by proposing a wide-area high-frequency impedance comparison based fault location technique. The high-frequency impedance model of DG is provided. Based on the constant DG impedance model in high-frequency range, the faulted line sections can be distinguished by comparing the measured impedance differences without requiring the exact distribution system parameters. Simulation results show that the proposed wide-area transient measurements based fault location method can provide accurate faulted sections in the distribution systems with DGs regardless of the load and DG output variations, measurement noise, unbalanced loads and islanding operations

Periodic Mechanical Stress Stimulates the FAK Mitogenic Signal in Rat Chondrocytes Through ERK1/2 Activity

Background/Aims: The biological effects of periodic mechanical stress on chondrocytes have been studied extensively over the past few years. However, the mechanisms underlying chondrocyte mechanosensing and signaling in response to periodic mechanical stress remain to be determined. In the current study, we examined the effects of focal adhesion kinase (FAK) signaling on periodic mechanical stress-induced chondrocyte proliferation and matrix synthesis. Methods and Results: Periodic mechanical stress significantly induced sustained phosphorylation of FAK at Tyr397 and Tyr576/577. Reduction of FAK with targeted shRNA via transfection of NH2-terminal tyrosine phosphorylation-deficient FAK mutant Y397F or Y576F-Y577F abolished periodic mechanical stress-induced chondrocyte proliferation and matrix synthesis, accompanied by attenuated ERK1/2 phosphorylation. However, activation of Src, PLCγ1 and Rac1 was not prevented upon FAK suppression. Furthermore, pretreatment with the Src-selective inhibitor, PP2, and shRNA targeted to Src or suppression of Rac1 with its selective inhibitor, NSC23766, blocked FAK phosphorylation at Tyr,576/577 but not Tyr,397 under periodic mechanical stress. Interestingly, FAK phosphorylation neither at Tyr397 nor at Tyr576/577 was affected by PLCγ1 depletion when periodic mechanical stress was applied. In addition, Tyr397 and Tyr576/577 phosphorylation levels were reduced upon pretreatment with a blocking antibody against integrin β1 under conditions of periodic mechanical stress. Conclusion: Our findings collectively suggest that periodic mechanical stress promotes chondrocyte proliferation and matrix synthesis through at least two pathways, integrin β1-Src-Rac1-FAK(Tyr576/577)-ERK1/2 and integrin β1-FAK (Tyr397)-ERK1/2

On the damage tolerance of 3-D printed Mg-Ti interpenetrating-phase composites with bioinspired architectures.

Bioinspired architectures are effective in enhancing the mechanical properties of materials, yet are difficult to construct in metallic systems. The structure-property relationships of bioinspired metallic composites also remain unclear. Here, Mg-Ti composites were fabricated by pressureless infiltrating pure Mg melt into three-dimensional (3-D) printed Ti-6Al-4V scaffolds. The result was composite materials where the constituents are continuous, mutually interpenetrated in 3-D space and exhibit specific spatial arrangements with bioinspired brick-and-mortar, Bouligand, and crossed-lamellar architectures. These architectures promote effective stress transfer, delocalize damage and arrest cracking, thereby bestowing improved strength and ductility than composites with discrete reinforcements. Additionally, they activate a series of extrinsic toughening mechanisms, including crack deflection/twist and uncracked-ligament bridging, which enable crack-tip shielding from the applied stress and lead to "Γ"-shaped rising fracture resistance R-curves. Quantitative relationships were established for the stiffness and strengths of the composites by adapting classical laminate theory to incorporate their architectural characteristics

A robust 6-mRNA signature for prognosis prediction of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies worldwide. PDAC prognostic and diagnostic biomarkers are still being explored. The aim of this study is to establish a robust molecular signature that can improve the ability to predict PDAC prognosis. 155 overlapping differentially expressed genes between tumor and non-tumor tissues from three Gene Expression Omnibus (GEO) datasets were explored. A least absolute shrinkage and selection operator method (LASSO) Cox regression model was employed for selecting prognostic genes. We developed a 6-mRNA signature that can distinguish high PDAC risk patients from low risk patients with significant differences in overall survival (OS). We further validated this signature prognostic value in three independent cohorts (GEO batch, P < 0.0001; ICGC, P = 0.0036; Fudan, P = 0.029). Furthermore, we found that our signature remained significant in patients with different histologic grade, TNM stage, locations of tumor entity, age and gender. Multivariate cox regression analysis showed that 6-mRNA signature can be an independent prognostic marker in each of the cohorts. Receiver operating characteristic curve (ROC) analysis also showed that our signature possessed a better predictive role of PDAC prognosis. Moreover, the gene set enrichment analysis (GSEA) analysis showed that several tumorigenesis and metastasis related pathways were indeed associated with higher scores of risk. In conclusion, identifying the 6-mRNA signature could provide a valuable classification method to evaluate clinical prognosis and facilitate personalized treatment for PDAC patients. New therapeutic targets may be developed upon the functional analysis of the classifier genes and their related pathways

Rechallenge of immune checkpoint inhibitors in advanced non‐small cell lung cancer

Abstract Immune checkpoint inhibitor (ICI) rechallenge in non‐small cell lung cancer (NSCLC) is a promising therapeutic strategy. The situation for ICI rechallenge can be divided into three categories: adverse events (AEs); resistance to ICIs, and rechallenge becomes compulsive because of tumor relapse while the patients had completed a 2 year course of immunotherapy. However, these categories are still controversial and should be explored further. Through voting at the 6th Straits Summit Forum on Lung Cancer, in this study we summarize the consensus of 147 experts in ICI rechallenges. A total of 97.74% experts agreed to rechallenge; 48.87% experts rechallenge with the original drug, and the others rechallenge with a different drug; 40.3% agreed to rechallenge directly after progression; 88.06% experts agreed to ICI rechallenge with a combination regimen; and factors such as previous performance status score, PD‐1 expression, and age should also be considered. Understanding the the clinical studies in ICI rechallenge could bring us one step closer to understanding the consensus. In patients with advanced NSCLC who have suffered recurrent or distant metastasis after immunotherapy, the option of rechallenge with ICIs is a promising treatment option