Digital Twin Techniques for Power Electronics-Based Energy Conversion Systems : A Survey of Concepts, Application Scenarios, Future Challenges, and Trends

The steady increase in energy demands has led to ever-increasing “energy generation.” This, coupled with the need for higher efficiency, flexibility, and reliability, has boosted the use of power electronics in power and energy systems. Therefore, power electronics-based energy conversion systems (PEECSs) have become prominent in power generation, power transmission, and end user applications. Given the relevance of such systems, and by considering their trend of digitalization, it is crucial to establish digital and intelligent PEECSs. To this end, digital twins (DTs) can be adopted, as they integrate many cuttingedge information techniques to realize the life cycle management of complex systems by constructing real-time mappings of them. In this article, existing DT techniques for PEECSs are reviewed. The concept, system layers, and key technologies of DTs are described first. Some application cases of DTs are then elaborated. Finally, future trends and challenges of DTs are discussed to provide a valuable reference for subsequent research.acceptedVersionPeer reviewe

Nonthermal plasma-assisted catalysis NH3 decomposition for COx-free H2 production : A review

Hydrogen (H2) is recognized as a viable and environmentally friendly energy source, utilized across various domains, from large-scale chemical energy exports to small-scale power generation in remote areas. However, the storage and distribution costs of H2 present significant challenges. Ammonia (NH3) emerges as a carbon-free hydrogen carrier, backed by a robust international transport and storage infrastructure. On-site hydrogen production can be efficiently achieved through NH3 decomposition, predominantly via thermal catalysis. One innovative approach involves plasma technology, which utilizes NH3, alcohols, or hydrocarbons to produce pure hydrogen in plasma reactors. Nonthermal plasma (NTP) in particular, for NH3 decomposition and H2 production, has garnered considerable interest owing to its higher energy efficiency than thermal plasma systems. Furthermore, integrating NTP with catalysis, termed plasma-assisted catalysis, creates a synergistic effect, enhancing NH3 decomposition efficiency for H2 production through improved plasma-catalyst interactions. Consequently, NTP-catalysis holds the potential to revolutionize NH3 conversion and utilisation in the future. To date, there have been limited studies on NTP-assisted catalytic NH3 decomposition. This review article compiles the latest NTP-assisted catalytic NH3 decomposition methodologies for H2 production. It delves into the basics of plasma-assisted NH3 decomposition, including adsorption, desorption, and the synergistic processes during plasma catalysis. Additionally, it examines the impact of NTP on the chemical states and properties of various catalysts and provides a comprehensive analysis of the factors influencing NH3-plasma decomposition

Effect of Sciadonic Acid on Hepatic Lipid Metabolism in Obese Mice Induced by A High-fat Diet

Objective: To investigate the potential beneficial effects of sciadonic acid (SA) on improving obesity induced by a high-fat diet in mice. Methods: Forty-eight male C57BL/6 mice were adaptively fed for one week and then randomly divided into the following groups: Control group (C), positive control group (S), model group (M), low-dose sciadonic acid group (LSA), medium-dose sciadonic acid group (MSA), and high-dose sciadonic acid group (HSA). The modeling process lasted for 16 weeks, and the low and high-dose groups were orally administered different doses of SA solution at a fixed time each day. After the modeling period, potential mechanisms of SA in regulating lipid metabolism in obese mice were explored, including aspects such as blood lipid metabolism, hepatic fat metabolism, hepatic oxidative stress, hepatic lipid synthesis, and expression of metabolism-related genes. Results: The high-dose SA intervention in obese mice significantly decreased the levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) in serum, while increasing high-density lipoprotein cholesterol (HDL-C) (P<0.05). It inhibited weight gain, reduced epididymal fat accumulation, and improved liver tissue damage. Additionally, SA significantly increased the activities of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in mice (P<0.05), and significantly reduced the production of oxidative end products MDA (P<0.05), alleviated oxidative stress in vivo, and inhibited lipid synthesis by regulating the expression of genes related to lipid metabolism to improve lipid metabolism. Conclusion: SA could improve lipid metabolism disorders in obese mice by suppressing fat accumulation, alleviate oxidative stress, regulate lipid synthesis and metabolism

Epidemiology of Doublet/Multiplet Mutations in Lung Cancers: Evidence that a Subset Arises by Chronocoordinate Events

BACKGROUND: Evidence strongly suggests that spontaneous doublet mutations in normal mouse tissues generally arise from chronocoordinate events. These chronocoordinate mutations sometimes reflect "mutation showers", which are multiple chronocoordinate mutations spanning many kilobases. However, little is known about mutagenesis of doublet and multiplet mutations (domuplets) in human cancer. Lung cancer accounts for about 25% of all cancer deaths. Herein, we analyze the epidemiology of domuplets in the EGFR and TP53 genes in lung cancer. The EGFR gene is an oncogene in which doublets are generally driver plus driver mutations, while the TP53 gene is a tumor suppressor gene with a more typical situation in which doublets derive from a driver and passenger mutation. METHODOLOGY/PRINCIPAL FINDINGS: EGFR mutations identified by sequencing were collected from 66 published papers and our updated EGFR mutation database (www.egfr.org). TP53 mutations were collected from IARC version 12 (www-p53.iarc.fr). For EGFR and TP53 doublets, no clearly significant differences in race, ethnicity, gender and smoking status were observed. Doublets in the EGFR and TP53 genes in human lung cancer are elevated about eight- and three-fold, respectively, relative to spontaneous doublets in mouse (6% and 2.3% versus 0.7%). CONCLUSIONS/SIGNIFICANCE: Although no one characteristic is definitive, the aggregate properties of doublet and multiplet mutations in lung cancer are consistent with a subset derived from chronocoordinate events in the EGFR gene: i) the eight frameshift doublets (present in 0.5% of all patients with EGFR mutations) are clustered and produce a net in-frame change; ii) about 32% of doublets are very closely spaced (< or =30 nt); and iii) multiplets contain two or more closely spaced mutations. TP53 mutations in lung cancer are very closely spaced (< or =30 nt) in 33% of doublets, and multiplets generally contain two or more very closely spaced mutations. Work in model systems is necessary to confirm the significance of chronocoordinate events in lung and other cancers

Identification of a biomarker profile associated with resistance to neoadjuvant chemoradiation therapy in rectal cancer

OBJECTIVE: To identify a biomarker profile associated with tumor response to chemoradiation (CRT) in locally advanced rectal cancer. BACKGROUND: Rectal cancer response to neoadjuvant CRT is variable. Whereas some patients have a minimal response, others achieve a pathologic complete response (pCR) and have no viable cancer cells in their surgical specimens. Identifying biomarkers of response will help select patients more likely to benefit from CRT. METHODS: This study includes 132 patients with locally advanced rectal cancer treated with neoadjuvant CRT followed by surgery. Tumor DNA from pretreatment tumor biopsies and control DNA from paired normal surgical specimens was screened for mutations and polymorphisms in 23 genes. Genetic biomarkers were correlated with tumor response to CRT (pCR vs non-pCR), and the association of single or combined biomarkers with tumor response was determined. RESULTS: Thirty-three of 132 (25%) patients achieved a pCR and 99 (75%) patients had non-pCR. Three individual markers were associated with non-pCR; v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutation (P = 0.0145), cyclin D1 G870A (AA) polymorphism (P = 0.0138), and methylenetetrahydrofolate reductase (NAD(P)H) C677T (TT) polymorphism (P = 0.0120). Analysis of biomarker combinations revealed that none of the 27 patients with both tumor protein p53 (p53) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutations had a pCR. Further, in patients with both p53 and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutations or the cyclin D1 G870A (AA) polymorphism or the methylenetetrahydrofolate reductase (NAD(P)H) C677T (TT) polymorphism (n = 52) the association with non-pCR was further strengthened; 51 of 52 (98%) of patients were non-pCR. These biomarker combinations had a validity of more than 70% and a positive predictive value of 97% to 100%, predicting that patients harboring these mutation/polymorphism profiles will not achieve a pCR. CONCLUSIONS: A specific biomarker profile is strongly associated with non-pCR to CRT and could be used to select optimal oncologic therapy in rectal cancer patients. ClinicalTrials.org Identifier: NCT00335816

Analysis of Cancer Mutation Signatures in Blood by a Novel Ultra-Sensitive Assay: Monitoring of Therapy or Recurrence in Non-Metastatic Breast Cancer

BACKGROUND: Tumor DNA has been shown to be present both in circulating tumor cells in blood and as fragments in the plasma of metastatic cancer patients. The identification of ultra-rare tumor-specific mutations in blood would be the ultimate marker to measure efficacy of cancer therapy and/or early recurrence. Herein we present a method for detecting microinsertions/deletions/indels (MIDIs) at ultra-high analytical selectivity. MIDIs comprise about 15% of mutations. METHODS AND FINDINGS: We describe MIDI-Activated Pyrophosphorolysis (MAP), a method of ultra-high analytical selectivity for detecting MIDIs. The high analytical selectivity of MAP is putatively due to serial coupling of two rare events: heteroduplex slippage and mis-pyrophosphorolysis. MAP generally has an analytical selectivity of one mutant molecule per >1 billion wild type molecules and an analytical sensitivity of one mutant molecule per reaction. The analytical selectivity of MAP is about 100,000-fold better than that of our previously described method of Pyrophosphorolysis Activated Polymerization-Allele specific amplification (PAP-A) for detecting MIDIs. The utility of this method is illustrated in two ways. 1) We demonstrate that two EGFR deletions commonly found in lung cancers are not present in tissue from four normal human lungs (10(7) copies of gDNA each) or in blood samples from 10 healthy individuals (10(7) copies of gDNA each). This is inconsistent, at least at an analytical sensitivity of 10(-7), with the hypotheses of (a) hypermutation or (b) strong selection of these growth factor-mutated cells during normal lung development leads to accumulation of pre-neoplastic cells with these EGFR mutations, which sometimes can lead to lung cancer in late adulthood. Moreover, MAP was used for large scale, high throughput "gene pool" analysis. No germline or early embryonic somatic mosaic mutation was detected (at a frequency of >0.3%) for the 15/18 bp EGFR deletion mutations in 6,400 individuals, suggesting that early embryonic EGFR somatic mutation is very rare, inconsistent with hypermutation or strong selection of these deletions in the embryo. 2) The second illustration of MAP utility is in personalized monitoring of therapy and early recurrence in cancer. Tumor-specific p53 mutations identified at diagnosis in the plasma of six patients with stage II and III breast cancer were undetectable after therapy in four women, consistent with clinical remission, and continued to be detected after treatment in two others, reflecting tumor progression. CONCLUSIONS: MAP has an analytical selectivity of one part per billion for detection of MIDIs and an analytical sensitivity of one molecule. MAP provides a general tool for monitoring ultra-rare mutations in tissues and blood. As an example, we show that the personalized cancer signature in six out of six patients with non-metastatic breast cancer can be detected and that levels over time are correlated with the clinical course of disease

Genotype-Phenotype Correlation in NF1: Evidence for a More Severe Phenotype Associated with Missense Mutations Affecting NF1 Codons 844–848

Neurofibromatosis type 1 (NF1), a common genetic disorder with a birth incidence of 1:2,000–3,000, is characterized by a highly variable clinical presentation. To date, only two clinically relevant intragenic genotype-phenotype correlations have been reported for NF1 missense mutations affecting p.Arg1809 and a single amino acid deletion p.Met922del. Both variants predispose to a distinct mild NF1 phenotype with neither externally visible cutaneous/plexiform neurofibromas nor other tumors. Here, we report 162 individuals (129 unrelated probands and 33 affected relatives) heterozygous for a constitutional missense mutation affecting one of five neighboring NF1 codons—Leu844, Cys845, Ala846, Leu847, and Gly848—located in the cysteine-serine-rich domain (CSRD). Collectively, these recurrent missense mutations affect ∼0.8% of unrelated NF1 mutation-positive probands in the University of Alabama at Birmingham (UAB) cohort. Major superficial plexiform neurofibromas and symptomatic spinal neurofibromas were more prevalent in these individuals compared with classic NF1-affected cohorts (both p < 0.0001). Nearly half of the individuals had symptomatic or asymptomatic optic pathway gliomas and/or skeletal abnormalities. Additionally, variants in this region seem to confer a high predisposition to develop malignancies compared with the general NF1-affected population (p = 0.0061). Our results demonstrate that these NF1 missense mutations, although located outside the GAP-related domain, may be an important risk factor for a severe presentation. A genotype-phenotype correlation at the NF1 region 844–848 exists and will be valuable in the management and genetic counseling of a significant number of individuals

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis