Application of Time-Fractional Order Bloch Equation in Magnetic Resonance Fingerprinting

Magnetic resonance fingerprinting (MRF) is one novel fast quantitative imaging framework for simultaneous quantification of multiple parameters with pseudo-randomized acquisition patterns. The accuracy of the resulting multi-parameters is very important for clinical applications. In this paper, we derived signal evolutions from the anomalous relaxation using a fractional calculus. More specifically, we utilized time-fractional order extension of the Bloch equations to generate dictionary to provide more complex system descriptions for MRF applications. The representative results of phantom experiments demonstrated the good accuracy performance when applying the time-fractional order Bloch equations to generate dictionary entries in the MRF framework. The utility of the proposed method is also validated by in-vivo study.Comment: Accepted at 2019 IEEE 16th International Symposium on Biomedical Imaging (ISBI 2019

Isoliquiritigenin inhibits the survival of diffuse large B-cell lymphoma cells by regulating Akt/mTOR signaling pathway

Purpose: To investigate the effect of isoliquiritigenin (ISL) on diffuse large B-cell lymphoma (DLBCL) cells and its underlying mechanism of action.Methods: The DLBCL cell line OCI-Ly19 was used in this study. Cell proliferation was measured by MTT assay. Apoptosis was evaluated using flow cytometry. Phosphorylation of Akt and mTOR was assessed using Western blotting.Results: DLBCL cell proliferation was suppressed by ISL in a concentration-dependent manner. The number of apoptotic cells increased following ISL treatment in a concentration-dependent manner (p < 0.05). ISL treatment also stopped the cell cycle at the G1 phase in a concentration-dependent manner. Western blot analysis indicated that there was no significant Akt and mTOR expression in cells treated with 10, 20, or 50 μM ISL (p < 0.05). However, Akt and mTOR phosphorylation was upregulated following treatment with 10, 20, or 50 μM ISL in a concentration-dependent manner (p < 0.05).Conclusion: The results demonstrate that ISL inhibits DLBCL cell proliferation and promotes cell apoptosis by blocking the cell cycle transition from the G1 to S phase, which is mediated by the inactivation of the Akt/mTOR signaling pathway. Keywords: Isoliquiritigenin, Cell survival, Diffuse large B-cell lymphoma, Akt/mTOR signaling pathwa

Effects of different extracts of Cremastra appendiculata (D. Don) Makino Cremastra appendiculata (D. Don) Makino on apoptosis of A549 cells

Purpose: To investigate the effect of different extracts of Cremastra appendiculata (D. Don) Makino onapoptosis of A549 cells, and the underlying mechanism.Methods: The contents of colchicine in ethyl acetate and n-butanol extracts of Cremastra appendiculata(D. Don) Makino were determined using high performance liquid chromatography (HPLC). Lung cancerA549 cells cultured in vitro were divided into blank control, standard colchicine and Cremastra appendiculata (D. Don) Makino extract groups. The effect of different extract concentrations on proliferation of the cells was determined using methyl thiazolyl diphenyl-tetrazolium (MTT) assay, while apoptosis of A549 cells induced by the extracts was evaluated by flow cytometry (FC).Results: Compared with the standard colchicine group, there was no colchicine in the n-butanol and ethyl acetate extracts of Cremastra appendiculata. Results from MTT assay showed that the extract inhibited the proliferation of A549 cells (p < 0.05). Flow cytometry results showed that ethyl acetate extract significantly enhanced apoptosis in A549 cells (p < 0.05). However, n-butanol extract had no significant effect on the apoptosis of A549 cells (p < 0.05).Conclusion: The ethyl acetate extract of Cremastra appendiculata (D. Don) Makino induces apoptosis in lung cancer A549 cells. Therefore, there is a need for further research and development of antitumor drugs from the extract of Cremastra appendiculata (D. Don) Makino. Keywords: Cremastra appendiculata (D. Don) Makino, Colchicine, A549 cells, Apoptosi

Metabolic Profiling Analysis of the Alleviation Effect of Treatment with Baicalin on Cinnabar Induced Toxicity in Rats Urine and Serum

Objectives: Baicalin is the main bioactive flavonoid constituent isolated from Scutellaria baicalensis Georgi. The mechanisms of protection of liver remain unclear. In this study, 1H NMR-based metabonomics approach has been used to investigate the alleviation effect of Baicalin.Method:1H NMR metabolomics analyses of urine and serum from rats, was performed to illuminate the alleviation effect of Baicalin on mineral medicine (cinnabar)-induced liver and kidney toxicity.Results: The metabolic profiles of groups receiving Baicalin at a dose of 80 mg/kg were remarkably different from cinnabar, and meanwhile, the level of endogenous metabolites returned to normal compared to group cinnabar. PLS-DA scores plots demonstrated that the variation tendency of control and Baicalein are apart from Cinnabar. The metabolic profiles of group Baicalein were similar to those of group control. Statistics results were confirmed by the histopathological examination and biochemical assay.Conclusion: Baicalin have the alleviation effect to the liver and kidney damage induced by cinnabar. The Baicalin could regulate endogenous metabolites associated with the energy metabolism, choline metabolism, amino acid metabolism, and gut flora

PBRM1 acts as a p53 lysine-acetylation reader to suppress renal tumor growth.

p53 acetylation is indispensable for its transcriptional activity and tumor suppressive function. However, the identity of reader protein(s) for p53 acetylation remains elusive. PBRM1, the second most highly mutated tumor suppressor gene in kidney cancer, encodes PBRM1. Here, we identify PBRM1 as a reader for p53 acetylation on lysine 382 (K382Ac) through its bromodomain 4 (BD4). Notably, mutations on key residues of BD4 disrupt recognition of p53 K382Ac. The mutation in BD4 also reduces p53 binding to promoters of target genes such as CDKN1A (p21). Consequently, the PBRM1 BD4 mutant fails to fully support p53 transcriptional activity and is defective as a tumor suppressor. We also find that expressions of PBRM1 and p21 correlate with each other in human kidney cancer samples. Our findings uncover a tumor suppressive mechanism of PBRM1 in kidney cancer and provide a mechanistic insight into the crosstalk between p53 and SWI/SNF complexes

Type-II antiferromagnetic ordering in double perovskite oxide Sr2_2NiWO6_6

Magnetic double perovskite compounds provide a fertile playground to explore interesting electronic and magnetic properties. By complementary macroscopic characterizations, neutron powder diffraction measurements and first-principles calculations, we have performed comprehensive studies on the magnetic ordering in the double perovskite compound Sr$_2$NiWO$_6$. It is found by neutron diffraction to order magnetically in a collinear type-II antiferromagnetic structure in a tetragonal lattice with $k$ = (0.5, 0, 0.5) below $T\rm_N$ = 56 K. In the ground state, the ordered moment of the spin-1 Ni$^{2+}$ ions is determined to be 1.9(2) $\mu\rm_{B}$, indicating a significant quenching of the orbital moment. The Ni$^{2+}$ moments in Sr$_2$NiWO$_6$ are revealed to cant off the $c$ axis by 29.2$^{\circ}$, which is well supported by the first-principles magnetic anisotropy energy calculations. Furthermore, the in-plane and out-of-plane next-nearest-neighbor superexchange couplings ($J\rm_2$ and $J\rm_{2c}$) are found to play a dominant role in the spin Hamiltonian of Sr$_2$NiWO$_6$, which accounts for the stabilization of the type-II AFM structure as its magnetic ground state.Comment: 10 Pages, 6 figures, accepted for publication in Physical Review

Detection of Detached Ice-fragments at Martian Polar Scarps Using a Convolutional Neural Network

Repeated high-resolution imaging has revealed current mass wasting in the form of ice block falls at steep scarps of Mars. However, both the accuracy and efficiency of ice-fragments’ detection are limited when using conventional computer vision methods. Existing deep learning methods suffer from the problem of shadow interference and indistinguishability between classes. To address these issues, we proposed a deep learning-driven change detection model that focuses on regions of interest. A convolutional neural network simultaneously analyzed bitemporal images, i.e., pre- and postdetach images. An augmented attention module was integrated in order to suppress irrelevant regions such as shadows while highlighting the detached ice-fragments. A combination of dice loss and focal loss was introduced to deal with the issue of imbalanced classes and hard, misclassified samples. Our method showed a true positive rate of 84.2% and a false discovery rate of 16.9%. Regarding the shape of the detections, the pixel-based evaluation showed a balanced accuracy of 85% and an F1 score of 73.2% for the detached ice-fragments. This last score reflected the difficulty in delineating the exact boundaries of some events both by a human and the machine. Compared with five state-of-the-art change detection methods, our method can achieve a higher F1 score and surpass other methods in excluding the interference of the changed shadows. Assessing the detections of the detached ice-fragments with the help of previously detected corresponding shadow changes demonstrated the capability and robustness of our proposed model. Furthermore, the good performance and quick processing speed of our developed model allow us to efficiently study large-scale areas, which is an important step in estimating the ongoing mass wasting and studying the evolution of the martian polar scarps