316 research outputs found

    Energy stable and maximum bound principle preserving schemes for the Q-tensor flow of liquid crystals

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    In this paper, we propose two efficient fully-discrete schemes for Q-tensor flow of liquid crystals by using the first- and second-order stabilized exponential scalar auxiliary variable (sESAV) approach in time and the finite difference method for spatial discretization. The modified discrete energy dissipation laws are unconditionally satisfied for both two constructed schemes. A particular feature is that, for two-dimensional (2D) and a kind of three-dimensional (3D) Q-tensor flows, the unconditional maximum-bound-principle (MBP) preservation of the constructed first-order scheme is successfully established, and the proposed second-order scheme preserves the discrete MBP property with a mild restriction on the time-step sizes. Furthermore, we rigorously derive the corresponding error estimates for the fully-discrete second-order schemes by using the built-in stability results. Finally, various numerical examples validating the theoretical results, such as the orientation of liquid crystal in 2D and 3D, are presented for the constructed schemes

    Research on the Evolution of International Intellectual Property Trade Network and China's Competitiveness

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    China is already a big country in international patent application, but there is still a big gap from becoming an innovation power and a power in international intellectual property trade. Examining the patterns and evolution of international intellectual property trade helps to grasp the scale, internal characteristics, and development trends within the global intellectual property market, enabling a precise assessment of China's standing and competitiveness in the international intellectual property arena. This paper examines intellectual property royalty data from 66 key countries and regions. By analyzing the global intellectual property rights trade volume changes and China’s trade growth rates from 2000 to 2019 and using Social Network Analysis, it calculates indicators such as density, centralization, degree centrality, and weighted degree centrality to assess the evolution of the international intellectual property trade network and China's changing status within it. The findings indicate that intellectual property trade between countries has intensified, leading to more frequent trade interactions with a “coreperiphery” structure and small-world features. Over time, the centralization pattern in international intellectual property trade initially strengthened but later declined amid turmoil. Developed countries, notably the United States, saw a diminishing core position, while emerging nations experienced rapid growth. China exhibits strong competitiveness, showing a gradual improvement in its position. However, it faces a growing trade deficit and needs to enhance its international influence and position within the global value chain

    PDCD1 genes may protect against extraocular manifestations in Chinese Han patients with Vogt-Koyanagi-Harada syndrome

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    Purpose: To analyze the potential association of programmed cell death 1 (PDCD1) with Vogt-Koyanagi-Harada (VKH) syndrome in a Chinese Han population. Methods: Three single nucleotide polymorphism (SNPs), PD-1.3G/A, PD-1.5C/T, and PD-1.6G/A, were genotyped in 247 VKH patients and 289 age-, sex-, and ethnically-matched healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The associations of genotypes and alleles with VKH syndrome were analyzed. Results: All genotype distributions in healthy controls were in Hardy-Weinberg equilibrium. The genotype and allele frequencies of PD-1.3, PD-1.5, and PD-1.6 were not different between patients with VKH syndrome and healthy controls. No significant difference was observed according to the status of human leukocyte antigen (HLA)-DR4 and HLA-DRw53. Compared to the controls, lower frequencies of the PD-1.5C genotype and allele frequencies were observed in VKH patients with extraocular findings. Conclusions: PD-1.3 and PD-1.6 polymorphisms are not associated with the susceptibility to VKH syndrome in the Chinese Han population. However, PD-1.5 may be negatively associated with the occurrence of extraocular manifestations of VKH syndrome

    PO-243 Correlation between exercise performance and muscle electrical activity in Exercise-induced Fatigue Rats

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    Objective Assess the muscle contraction ability of rats before and after exercise fatigue quantitatively, and analyze the correlation between exercise performance and muscle electrical activity. This study intends to provide a theoretical principle for exercise fatigue. Methods 7 healthy adult male SD rats (300~350g) were used and trained for adaptive treadmill by running on the treadmill for 1 week and holding on a vertical rectangular railing (20×10cm, 10 iron bars) until it's mastered. After this training, we used rat grasping force tester( BioSEB GS3) to measure the maximum grasping force(MGF) of rat's limbs, each rat was carried out 3 times, bout interval is 2 minutes. In addition, the grasping bar time(GBT) was recorded 3 times , bout interval is 30 minutes. We let rats to grasp and hold on a vertical rectangular railing(20×10cm, 10 iron bars), evaluation of rat muscular endurance by grasping bar time(GBT), each rat was carried out 3 times, bout interval is 30 minutes; During the MGF and GBT test, motor unit recruitment and discharge frequency was predicted by measuring the EMG of extensor muscles of the right hindlimb and flexor elbow muscles of the right forelimb by wireless non-invasive miniature surface EMG tester (Italy, BTS FREEEMG), the max Root Mean Square (maxRMS) and Median Frequency (MF) parameter was used to evaluate motor unit recruitment and discharge frequency, respectively. After these, the rats were allowed to have a one-day rest, and then had a load motion program on the treadmill (three levels’ load: the first stage movement speed 8.2 m/min, exercise time 15 min; second stage speed 15 m/min, exercise time 15 min; third stage speed at 20 m/min, exercise to fatigue ) to build the rats EF model by monitoring the acceleration of the rat's sprint with a miniature wireless acceleration sensor (18g). 30 continuous sprint acceleration at the end of running was less than half of initial acceleration and the running posture of the rats changed to prostrate, and remained at the end of the runway for a long time. Later, quantitative correlational data analyses such as mean, Pearson correlation, analysis of one-way ANOVA and paired sample t test were performed in this study. Results (1) The rats’ sprint acceleration of treadmill exercise at the end stage (the final 1/5 of the total time) decreased by 56.9% (P < 0.01) when compared with the early stage (the begining 1/5 of the total time). (2) The MGF and GBT of EF decreased by 68.1% (P < 0.01) and 90.38% (P < 0.01), respectively when compared with the beginning EF; in addition, the EMG maxRMS and MF of hindlimb and forelimb of EF rats had significantly reduced (P < 0.01), and the rats’ MGF/GBT was positively correlated with EMG maxRMS/MF significantly (MGF: forelimb rmaxRMS = 0.901, P < 0.01,rMF = 0.761, P < 0.01; hindlimb rmaxRMS = 0.913, P < 0.01,rMF = 0.783, P < 0.01; GBT: forelimb rmaxRMS = 0.922, P < 0.01,rMF = 0.806, P < 0.01; hindlimb rmaxRMS = 0.908, P < 0.01,rMF = 0.896, P < 0.01). Conclusions  Exercise fatigue reduced the muscle strength, muscular endurance and muscle power of rates significantly, which may be related to the decreased recruitment, rhythm synchronization and discharge frequency of muscle motor units of forelimb flexor and hindlimb extensor

    Interlayer ferroelectric polarization modulated anomalous Hall effects in four-layer MnBi2Te4 antiferromagnets

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    Van der Waals (vdW) assembly could efficiently modulate the symmetry of two-dimensional (2D) materials that ultimately governs their physical properties. Of particular interest is the ferroelectric polarization being introduced by proper vdW assembly that enables the realization of novel electronic, magnetic and transport properties of 2D materials. Four-layer antiferromagnetic MnBi2Te4 (F-MBT) offers an excellent platform to explore ferroelectric polarization effects on magnetic order and topological transport properties of nanomaterials. Here, by applying symmetry analyses and density-functional-theory calculations, the ferroelectric interface effects on magnetic order, anomalous Hall effect (AHE) or even quantum AHE (QAHE) on the F-MBT are analyzed. Interlayer ferroelectric polarization in F-MBT efficiently violates the PT symmetry (the combination symmetry of central inversion (P) and time reverse (T) of the F-MBT by conferring magnetoelectric couplings, and stabilizes a specific antiferromagnetic order encompassing a ferromagnetic interface in the F-MBT. We predict that engineering an interlayer polarization in the top or bottom interface of F-MBT allows converting F-MBT from a trivial insulator to a Chern insulator. The switching of ferroelectric polarization at the middle interfaces results in a direction reversal of the quantum anomalous Hall current. Additionally, the interlayer polarization of the top and bottom interfaces can be aligned in the same direction, and the switching of polarization direction also reverses the direction of anomalous Hall currents. Overall, our work highlights the occurrence of quantum-transport phenomena in 2D vdW four-layer antiferromagnets through vdW assembly. These phenomena are absent in the bulk or thin-film in bulk-like stacking forms of MnBi2Te4

    CDK6 is essential for mesenchymal stem cell proliferation and adipocyte differentiation

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    Background: Overweight or obesity poses a significant risk of many obesity-related metabolic diseases. Among all the potential new therapies, stem cell-based treatments hold great promise for treating many obesity-related metabolic diseases. However, the mechanisms regulating adipocyte stem cells/progenitors (precursors) are unknown. The aim of this study is to investigate if CDK6 is required for mesenchymal stem cell proliferation and adipocyte differentiation.Methods: Cyclin-dependent kinase 6 (Cdk6) mouse models together with stem cells derived from stromal vascular fraction (SVF) or mouse embryonic fibroblasts (MEFs) of Cdk6 mutant mice were used to determine if CDK6 is required for mesenchymal stem cell proliferation and adipocyte differentiation.Results: We found that mice with a kinase inactive CDK6 mutants (K43M) had fewer precursor residents in the SVF of adult white adipose tissue (WAT). Stem cells from the SVF or MEFs of K43M mice had defects in proliferation and differentiation into the functional fat cells. In contrast, mice with a constitutively active kinase CDK6 mutant (R31C) had the opposite traits. Ablation of RUNX1 in both mature and precursor K43M cells, reversed the phenotypes.Conclusion: These results represent a novel role of CDK6 in regulating precursor numbers, proliferation, and differentiation, suggesting a potential pharmacological intervention for using CDK6 inhibitors in the treatment of obesity-related metabolic diseases

    Serum cytokines and neutrophil-to-lymphocyte ratio as predictive biomarkers of benefit from PD-1 inhibitors in gastric cancer

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    BackgroundImmunotherapy is significantly revolutionizing cancer treatment and demonstrating promising efficacy in gastric cancer (GC) patients. However, only a subset of patients could derive benefits from targeted monoclonal antibody therapy against programmed death receptor 1 (PD-1). This study aims to identify suitable serum cytokines and blood cell ratios as predictive biomarkers to aid in the selection of GC patients likely to benefit from PD-1 inhibitors.Materials and methodsThis retrospective study included 41 GC patients who received PD-1 inhibitors combined with chemotherapy, 36 GC patients treated solely with chemotherapy, and 33 healthy controls. The study assessed the levels of seven cytokines: interleukin-2 (IL-2), IL-4, IL-6, IL-10, IL-17A, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and various inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR), total lymphocyte count (TLC), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR). Measurements were obtained using the inpatient system. Univariate and multivariate Cox regression analyses were performed to evaluate the predictive significance of these hematologic parameters for clinical outcomes.ResultsLevels of IL-6, IL-10, TNF-α, NLR, and PLR were significantly elevated in GC patients compared to healthy controls, while TLC and LMR were higher in the control group. Among the 41 patients receiving PD-1 inhibitors and chemotherapy, baseline IL-2 was associated with OS and PFS. Additionally, IL-6 and IL-17A correlated with OS, while NLR was linked to PFS (all P<0.05). These factors were identified as independent prognostic indicators in both univariate and multivariate analyses. Furthermore, almost all cytokine levels increased following the initiation of PD-1 inhibitor treatment.ConclusionsThe introduction of PD-1 inhibitors alongside chemotherapy in GC impacts serum cytokine levels. IL-2, IL-6, IL-17A, and NLR exhibit potential as reliable circulating predictive biomarkers for identifying patients who may benefit from PD-1 inhibitors combined with chemotherapy

    Dysregulation of protein succinylation and disease development

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    As a novel post-translational modification of proteins, succinylation is widely present in both prokaryotes and eukaryotes. By regulating protein translocation and activity, particularly involved in regulation of gene expression, succinylation actively participates in diverse biological processes such as cell proliferation, differentiation and metabolism. Dysregulation of succinylation is closely related to many diseases. Consequently, it has increasingly attracted attention from basic and clinical researchers. For a thorough understanding of succinylation dysregulation and its implications for disease development, such as inflammation, tumors, cardiovascular and neurological diseases, this paper provides a comprehensive review of the research progress on abnormal succinylation. This understanding of association of dysregulation of succinylation with pathological processes will provide valuable directions for disease prevention/treatment strategies as well as drug development
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