356 research outputs found

    Weighted Fusion Robust Steady-State Kalman Filters for Multisensor System with Uncertain Noise Variances

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    A direct approach of designing weighted fusion robust steady-state Kalman filters with uncertain noise variances is presented. Based on the steady-state Kalman filtering theory, using the minimax robust estimation principle and the unbiased linear minimum variance (ULMV) optimal estimation rule, the six robust weighted fusion steady-state Kalman filters are designed based on the worst-case conservative system with the conservative upper bounds of noise variances. The actual filtering error variances of each fuser are guaranteed to have a minimal upper bound for all admissible uncertainties of noise variances. A Lyapunov equation method for robustness analysis is proposed. Their robust accuracy relations are proved. A simulation example verifies their robustness and accuracy relations

    Determination of geopotential difference by hydrogen masers based on precise point positioning time-frequency transfer

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    According to the general relativity theory, the geopotential difference can be determined by gravity frequency shift between two clocks. Here we report on the experiments to determine the geopotential difference between two remote sites by hydrogen masers based on precise point positioning time-frequency transfer technique. The experiments include the remote clock comparison and the local clock comparison using two CH1-95 active hydrogen masers linked with global navigation satellite system time-frequency receivers. The frequency difference between two hydrogen masers at two sites is derived from the time difference series resolved by the above-mentioned technique. Considering the local clock comparison as calibration, the determined geopotential difference by our experiments is 12,142.3 (112.4) m^2/s^2, quite close to the value 12,153.3 (2.3) m^2/s^2 computed by the EIGEN-6C4 model. Results show that the proposed approach here for determining geopotential difference is feasible, operable, and promising for applications in various fields.Comment: 12 pages, 4 figure

    Prevention and Potential Treatment Strategies for Respiratory Syncytial Virus

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    Respiratory syncytial virus (RSV) is a significant viral pathogen that causes respiratory infections in infants, the elderly, and immunocompromised individuals. RSV-related illnesses impose a substantial economic burden worldwide annually. The molecular structure, function, and in vivo interaction mechanisms of RSV have received more comprehensive attention in recent times, and significant progress has been made in developing inhibitors targeting various stages of the RSV replication cycle. These include fusion inhibitors, RSV polymerase inhibitors, and nucleoprotein inhibitors, as well as FDA-approved RSV prophylactic drugs palivizumab and nirsevimab. The research community is hopeful that these developments might provide easier access to knowledge and might spark new ideas for research programs

    Effects of RNA interference-mediated gene silencing of JMJD2A on human breast cancer cell line MDA-MB-231 in vitro

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    Previous data demonstrate that JMJD2A is a cancer-associated gene and may be involved in human breast cancer by demethylation of H3K9me3. The aim of this study was to investigate depressive effects on JMJD2A by transfection with JMJD2A-sepcific siRNA in human breast cancer cell line MDA-MB-231 and effects on cell proliferation, invasion and migration. JMJD2A-specific siRNA was chemically synthesised and transfected into human breast cancer cell line MDA-MB-231. Expression levels of JMJD2A were detected by quantitative real-time PCR and Western blot analysis. Cells proliferation was evaluated by using flow cytometric anlysis and MTT assay. The abilities of invasion and migration were evaluated by cell migration and invasion assay with Boyden chambers. The results showed that the transfection was successful and expression levels of JMJD2A mRNA and protein in siRNA group were both down-regulated. By MTT assay, the mean actual absorbance in siRNA group was significantly lower than that in blank control group (P < 0.05) and negative control group (P < 0.05). In addition, the percentage of cells in G0/G1 phase in siRNA group was significantly more than that in blank control group (P < 0.05) and negative control group (P < 0.05). Furthermore, by cell invasion and migration assay, the decreased number of migrated cells in siRNA group was observed (P < 0.05). These data imply that silencing JMJD2A gene could result in cell cycle change and proliferation inhibition, and lead to suppress tumor cell invasion and migration. It provides a new perspective in understanding the pleiotropic functions of JMJD2A and its contribution to human breast cancer

    Prognostic models for mucinous and non-specific adeno cholangiocarcinoma: a population-based retrospective study

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    BackgroundClinically, the diagnosis and treatment of cholangiocarcinoma are generally different according to the location of occurrence, and the studies rarely consider the differences between different pathological types. Cholangiocarcinomas in large- and middle-sized intrahepatic bile ducts are mostly mucinous, while in small sized bile duct are not; mucinous extrahepatic cholangiocarcinomas are also more common than mucinous intrahepatic cholangiocarcinoma. However, it is unclear whether these pathological type differences are related to the prognosis.MethodsData of total 22509 patients was analyzed from Surveillance, Epidemiology, and End Results program database out of which 22299 patients were diagnosed with common adeno cholangiocarcinoma while 210 were diagnosed with mucinous cholangiocarcinoma. Based on the propensity score matching (PSM) analysis, between these two groups’ clinical, demographic, and therapeutic features were contrasted. The data were analyzed using Cox and LASSO regression analysis and Kaplan-Meier survival curves. Ultimately, overall survival (OS) and cancer specific survival (CSS) related prognostic models were established and validated in test and external datasets and nomograms were created to forecast these patients’ prognosis.ResultsThere was no difference in prognosis between mucinous cholangiocarcinoma and adeno cholangiocarcinoma. Therefore, we constructed prognostic model and nomogram that can be used for mucinous and adeno cholangiocarcinoma at the same time. By comparing the 9 independent key characteristics i.e. Age, tumor size, the number of primary tumors, AJCC stage, Grade, lymph node status, metastasis, surgery and chemotherapy, risk scores were calculated for each individual. By integrating these two pathological types in OS and CSS prognostic models, effective prognosis prediction results could be achieved in multiple datasets (OS: AUC 0.70–0.87; CSS: AUC 0.74–0.89).ConclusionAge, tumor size, the number of primary tumors, AJCC stage, Grade, lymph node status, metastasis, surgery and chemotherapy are the independent prognostic factors in OS or CSS of the patients with mucinous and ordinary cholangiocarcinoma. Nomogram that can be used for mucinous and adeno cholangiocarcinoma at the same time is of significance in clinical practice and management of cholangiocarcinoma

    Pulsatilla decoction alleviates DSS-induced UC by activating FXR-ASBT pathways to ameliorate disordered bile acids homeostasis

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    Ethnopharmacological relevance: Pulsatilla decoction (PD) is a classical prescription for the treatment of ulcerative colitis. Previous studies have demonstrated that the therapeutic efficacy of PD is closely associated with the activation of Farnesoid X receptor (FXR). The activity of FXR is regulated by apical sodium-dependent bile acid transporter (ASBT), and the FXR-ASBT cascade reaction, centered around bile acid receptor FXR, plays a pivotal role in maintaining bile acid metabolic homeostasis to prevent the occurrence and progression of ulcerative colitis (UC).Aim of the study: To elucidate the underlying mechanism by which PD exerts its proteactive effects against Dextran Sulfate Sodium Salt (DSS)-induced ulcerative colitis, focusing on the modulation of FXR and ASBT.Materials and methods: To establish a model of acute ulcerative colitis, BALB/C mice were administered 3.5% DSS in their drinking water for consecutive 7 days. The disease activity index (DAI) was employed to evaluate the clinical symptoms exhibited by each group of mice. Goblet cell expression in colon tissue was assessed using glycogen schiff periodic acid-Schiff (PAS) and alcian blue staining techniques. Inflammatory cytokine expression in serum and colonic tissues was examined through enzyme-linked immunosorbent assay (ELISA). A PCR Array chip was utilized to screen 88 differential genes associated with the FXR-ASBT pathway in UC treatment with PD. Western blotting (WB) analysis was performed to detect protein expression levels of differentially expressed genes in mouse colon tissue.Results: The PD treatment effectively reduced the Disease Activity Index (DAI) score and mitigated colon histopathological damage, while also restoring weight and colon length. Furthermore, it significantly alleviated the severity of ulcerative colitis (UC), regulated inflammation, modulated goblet cell numbers, and restored bile acid balance. Additionally, a PCR Array analysis identified 21 differentially expressed genes involved in the FXR-ASBT pathway. Western blot results demonstrated significant restoration of FXR, GPBAR1, CYP7A1, and FGF15 protein expression levels following PD treatment; moreover, there was an observed tendency towards increased expression levels of ABCB11 and RXRα.Conclusion: The therapeutic efficacy of PD in UC mice is notable, potentially attributed to its modulation of bile acid homeostasis, enhancement of gut barrier function, and attenuation of intestinal inflammation
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