282 research outputs found

    Characterization of the Complete Mitochondrial Genomes of Cnaphalocrocis medinalis and Chilo suppressalis (Lepidoptera: Pyralidae)

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    The complete mitochondrial genomes (mitogenomes) of Cnaphalocrocis medinalis and Chilo suppressalis (Lepidoptera: Pyralidae) were determined and analyzed. The circular genomes were 15,388 bp long for C. medinalis and 15,395 bp long for C. suppressalis. Both mitogenomes contained 37 genes, with gene order similar to that of other lepidopterans. Notably, 12 protein-coding genes (PCGs) utilized the standard ATN, but the cox1 gene used CGA as the initiation codon; the cox1, cox2, and nad4 genes in the two mitogenomes had the truncated termination codons T, T, and TA, respectively, but the nad5 gene was found to use T as the termination codon only in the C. medinalis mitogenome. Additionally, the codon distribution and Relative Synonymous Codon Usage of the 13 PCGs in the C. medinalis mitogenome were very different from those in other pyralid moth mitogenomes. Most of the tRNA genes had typical cloverleaf secondary structures. However, the dihydrouridine (DHU) arm of the trnS1(AGN) gene did not form a stable stem-loop structure. Forty-nine helices in six domains, and 33 helices in three domains were present in the secondary structures of the rrnL and rrnS genes of the two mitogenomes, respectively. There were four major intergenic spacers, except for the A+T-rich region, spanning at least 12 bp in the two mitogenomes. The A+T-rich region contained an 'ATAGT(A)'-like motif followed by a poly-T stretch in the two mitogenomes. In addition, there were a potential stem-loop structure, a duplicated 25-bp repeat element, and a microsatellite '(TA)13' observed in the A+T-rich region of the C. medinalis mitogenome. A poly-T motif, a duplicated 31-bp repeat element, and a 19-bp triplication were found in the C. suppressalis mitogenome. However, there are many differences in the A+T-rich regions between the C. suppressalis mitogenome sequence in the present study and previous reports. Finally, the phylogenetic relationships of these insects were reconstructed based on amino acid sequences of mitochondrial 13 PCGs using Bayesian inference and maximum likelihood methods. These molecular-based phylogenies support the traditional morphologically based view of relationships within the Pyralidae

    Dynamic radiomics for predicting the efficacy of antiangiogenic therapy in colorectal liver metastases

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    Background and objectiveFor patients with advanced colorectal liver metastases (CRLMs) receiving first-line anti-angiogenic therapy, an accurate, rapid and noninvasive indicator is urgently needed to predict its efficacy. In previous studies, dynamic radiomics predicted more accurately than conventional radiomics. Therefore, it is necessary to establish a dynamic radiomics efficacy prediction model for antiangiogenic therapy to provide more accurate guidance for clinical diagnosis and treatment decisions.MethodsIn this study, we use dynamic radiomics feature extraction method that extracts static features using tomographic images of different sequences of the same patient and then quantifies them into new dynamic features for the prediction of treatmentefficacy. In this retrospective study, we collected 76 patients who were diagnosed with unresectable CRLM between June 2016 and June 2021 in the First Hospital of China Medical University. All patients received standard treatment regimen of bevacizumab combined with chemotherapy in the first-line treatment, and contrast-enhanced abdominal CT (CECT) scans were performed before treatment. Patients with multiple primary lesions as well as missing clinical or imaging information were excluded. Area Under Curve (AUC) and accuracy were used to evaluate model performance. Regions of interest (ROIs) were independently delineated by two radiologists to extract radiomics features. Three machine learning algorithms were used to construct two scores based on the best response and progression-free survival (PFS).ResultsFor the task that predict the best response patients will achieve after treatment, by using ROC curve analysis, it can be seen that the relative change rate (RCR) feature performed best among all features and best in linear discriminantanalysis (AUC: 0.945 and accuracy: 0.855). In terms of predicting PFS, the Kaplan–Meier plots suggested that the score constructed using the RCR features could significantly distinguish patients with good response from those with poor response (Two-sided P<0.0001 for survival analysis).ConclusionsThis study demonstrates that the application of dynamic radiomics features can better predict the efficacy of CRLM patients receiving antiangiogenic therapy compared with conventional radiomics features. It allows patients to have a more accurate assessment of the effect of medical treatment before receiving treatment, and this assessment method is noninvasive, rapid, and less expensive. Dynamic radiomics model provides stronger guidance for the selection of treatment options and precision medicine

    Diaqua­bis(2,2′-biimidazole)cobalt(II) 4,4′-dicarboxy­biphenyl-3,3′-di­car­boxylate

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    In the title compound, [Co(C6H6N4)2(H2O)2](C16H8O8), the CoII cation and the organic anion occupy different crystallographic inversion centres and, as a consequence, the asymmetric unit comprises two half-mol­ecules. The benzene groups are coplanar. The four coordinating N atoms of the two bidentate biimidazole ligands define the equatorial plane of a slightly distorted octa­hedral CoO2N4 geometry, and the water O atoms lie in the axial coordination sites. Translational (a,) and inversion-related symmetry operations link the Co complex mol­ecules and the negatively charged carboxyl­ate anions via inter­molecular N—H⋯O and O—H⋯O hydrogen bonds into sheets parallel to (01). The coordinated water mol­ecules connect the sheets through O—H⋯O hydrogen bonds, forming a three-dimensional framework. In addition, two intra­molecular O—H⋯O hydrogen bonds are observed between the carboxyl and carboxyl­ate groups

    Warming effect of dust aerosols modulated by overlapping clouds below

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    Due to the substantial warming effect of dust aerosols overlying clouds and its poor representation in climate models, it is imperative to accurately quantify the direct radiative forcing (DRF) of above-cloud dust aerosols. When absorbing aerosol layers are located above clouds, the warming effect of aerosols strongly depends on the cloud macro- and micro-physical properties underneath, such as cloud optical depth and cloud fraction at visible wavelength. A larger aerosol-cloud overlap is believed to cause a larger warming effect of absorbing aerosols, but the influence of overlapping cloud fraction and cloud optical depth remains to be explored. In this study, the impact of overlapping cloud properties on the shortwave all-sky DRF due to springtime above-cloud dust aerosols is quantified over northern Pacific Ocean based on 10-year satellite measurements. On average, the DRF is roughly 0.62 Wm^(−2). Furthermore, the warming effect of dust aerosols linearly increases with both overlapping cloud fraction and cloud optical depth. An increase of 1% in overlapping cloud fraction will amplify this warming effect by 1.11 Wm^(−2)τ^(−1). For the springtime northern Pacific Ocean, top-of-atmosphere cooling by dust aerosols turns into warming when overlapping cloud fraction is beyond 0.20. The variation of critical cloud optical depth beyond which dust aerosols switch from exerting a net cooling to a net warming effect depends on the concurrent overlapping cloud fraction. When the overlapping cloud coverage range increases from 0.2 to –0.4 to 0.6–0.8, the corresponding critical cloud optical depth reduces from 6.92 to 1.16. Our results demonstrate the importance of overlapping cloud properties for determining the springtime warming effect of dust aerosols

    Altered fluvial patterns in North China indicate rapid climate change linked to the Permian-Triassic mass extinction

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    The causes of the severest crisis in the history of life around the Permian-Triassic boundary (PTB) remain controversial. Here we report that the latest Permian alluvial plains in Shanxi, North China, went through a rapid transition from meandering rivers to braided rivers and aeolian systems. Soil carbonate carbon isotope (δ13C), oxygen isotope (δ18O), and geochemical signatures of weathering intensity reveal a consistent pattern of deteriorating environments (cool, arid, and anoxic conditions) and climate fluctuations across the PTB. The synchronous ecological collapse is confirmed by a dramatic reduction or disappearance of dominant plants, tetrapods and invertebrates and a bloom of microbially-induced sedimentary structures. A similar rapid switch in fluvial style is seen worldwide (e.g. Karoo Basin, Russia, Australia) in terrestrial boundary sequences, all of which may be considered against a background of global marine regression. The synchronous global expansion of alluvial fans and high-energy braided streams is a response to abrupt climate change associated with aridity, hypoxia, acid rain, and mass wasting. Where neighbouring uplands were not uplifting or basins subsiding, alluvial fans are absent, but in these areas the climate change is evidenced by the disruption of pedogenesis
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