Recent advances of ferroptosis in tumor: From biological function to clinical application

Ferroptosis is a recently recognized form of cell death with distinct features in terms of morphology, biochemistry, and molecular mechanisms. Unlike other types of cell death, ferroptosis is characterized by iron dependence, reactive oxygen species accumulation and lipid peroxidation. Recent studies have demonstrated that selective autophagy plays a vital role in the induction of ferroptosis, including ferritinophagy, lipophagy, clockophagy, and chaperone-mediated autophagy. Emerging evidence has indicated the involvement of ferroptosis in tumorigenesis through regulating various biological processes, including tumor growth, metastasis, stemness, drug resistance, and recurrence. Clinical and preclinical studies have found that novel therapies targeting ferroptosis exert great potential in the treatment of tumors. This review provides a comprehensive overview of the molecular mechanisms in ferroptosis, especially in autophagy-driven ferroptosis, discusses the recent advances in the biological roles of ferroptosis in tumorigenesis, and highlights the application of novel ferroptosis-targeted therapies in the clinical treatment of tumors

Circulating current suppression in modular multilevel converters with even-harmonic repetitive control

Due to voltage mismatch between phase legs and the dc bus in modular multilevel converters (MMCs), the differential current in MMCs is inherently subjected to circulating even-order harmonics. Repetitive control based active harmonic suppression methods can be adopted to eliminate such harmonics. Nevertheless, conventional repetitive controllers have a relatively slow dynamic response, because all the sampled errors in the past one cycle have to be stored, which causes a response delay for one fundamental period. This paper proposes an improved repetitive control scheme that exclusively copes with even-order harmonics based on the circulating current characteristics of MMC systems. The design details of the even harmonic repetitive control scheme according to the harmonics characteristics are provided. The proposed even-harmonic repetitive control scheme requires halved data memory to store error samplings and the delay introduced by the repetitive controller is also reduced. According to the frequency domain analysis, the even-harmonic repetitive control features faster convergence rate, greater low-frequency gains, higher crossover frequency, and higher tolerance against system frequency deviation, while possessing the same even-order harmonics suppression capability and stability as conventional ones. Simulation and experimental results are presented to show the steady-state harmonics suppression capability, dynamic response, and disturbance tolerance of the proposed even-harmonic repetitive control scheme.Accepted versio

Quantitative metagenomics reveals unique gut microbiome biomarkers in ankylosing spondylitis

Abstract Background The assessment and characterization of the gut microbiome has become a focus of research in the area of human autoimmune diseases. Ankylosing spondylitis is an inflammatory autoimmune disease and evidence showed that ankylosing spondylitis may be a microbiome-driven disease. Results To investigate the relationship between the gut microbiome and ankylosing spondylitis, a quantitative metagenomics study based on deep shotgun sequencing was performed, using gut microbial DNA from 211 Chinese individuals. A total of 23,709 genes and 12 metagenomic species were shown to be differentially abundant between ankylosing spondylitis patients and healthy controls. Patients were characterized by a form of gut microbial dysbiosis that is more prominent than previously reported cases with inflammatory bowel disease. Specifically, the ankylosing spondylitis patients demonstrated increases in the abundance of Prevotella melaninogenica, Prevotella copri, and Prevotella sp. C561 and decreases in Bacteroides spp. It is noteworthy that the Bifidobacterium genus, which is commonly used in probiotics, accumulated in the ankylosing spondylitis patients. Diagnostic algorithms were established using a subset of these gut microbial biomarkers. Conclusions Alterations of the gut microbiome are associated with development of ankylosing spondylitis. Our data suggest biomarkers identified in this study might participate in the pathogenesis or development process of ankylosing spondylitis, providing new leads for the development of new diagnostic tools and potential treatments

Correction to: Quantitative metagenomics reveals unique gut microbiome biomarkers in ankylosing spondylitis

Abstract Upon publication of the original article [1], it was noted that references 11 and 22 were miscited in the reference list