Vliv globální finanční krize na volatilitu akciových trhů

Import 22/07/2015The main aim of this thesis is to model effect of global financial crisis on volatility of stock markets using conditional volatility models. For the purpose of this thesis, we utilize daily time series of Chinese and Japanese stock markets covering the period from January 2006 till March 2015. Chinese stock market is represented by Shanghai Composite Index while Japanese market is approximated by Nikkei 225 Index. The main purpose of this thesis is supported by two sub-goals: the first sub-goal is to measure whether the linear or non-linear model can better match the actual volatility on stock index under a certain sub-period for either Chinese market or Japanese market; the second sub-goal is to investigate potential existence of leverage effect for Chinese and Japanese stock market.The main aim of this thesis is to model effect of global financial crisis on volatility of stock markets using conditional volatility models. For the purpose of this thesis, we utilize daily time series of Chinese and Japanese stock markets covering the period from January 2006 till March 2015. Chinese stock market is represented by Shanghai Composite Index while Japanese market is approximated by Nikkei 225 Index. The main purpose of this thesis is supported by two sub-goals: the first sub-goal is to measure whether the linear or non-linear model can better match the actual volatility on stock index under a certain sub-period for either Chinese market or Japanese market; the second sub-goal is to investigate potential existence of leverage effect for Chinese and Japanese stock market.154 - Katedra financívýborn

Clinical characteristics and related influencing factors of common rheumatic diseases concomitant with tuberculosis

ObjectiveTo explore the clinical characteristics and risk factors of common systemic rheumatism concomitant with tuberculosis (TB).MethodsA total of 3,906 patients of RA, SLE, and SS diagnosed in the People's Hospital of Sichuan Province from January 2007 to January 2017 were collected. One hundred and five patients with TB were included as TB group, including 42 RA, 41 SLE, and 22 SS patients. In the non-TB group, 84 RA, 82 SLE, and 44 SS patients were randomly selected during the same period.ResultsFever was the most common symptom among RA, SLE, and SS patients with TB, accounting for 83.3%, 92.7%, and 68.2%, respectively. Cough, weight loss or fatigue were the next common. RA patients with TB were mostly pulmonary TB (PTB), accounting for 64.3%. The proportion of PTB for SLE and SS were 46.3%, 59.01%, respectively. In TB group, 59% RA, 57% SLE, and 62% SS with PTB had two or more chest CT findings. There were 48 TB cases received both Interferon Gamma Release Assay (IGRA) and Tuberculin skin test (TST) with positive rates of 91.8%, 45.8%, respectively. The daily average dose of glucocorticoids within 1 year in TB group was higher than that in non-TB group of SLE patients, lower counts of CD4+ T cell count were found in TB group (P < 0.05), while no such differences were found in RA and SS patients.ConclusionRA patients with TB are mainly pulmonary TB. For SLE and SS patients, the chance of PTB and extrapulmonary tuberculosis is similar. Daily average dose of glucocorticoids within 1 year may be a common risk factor for RA, SLE and SS patients developing TB. Decreased CD4+ T cell count may also be a risk factor for SLE patients with TB. Symptoms of RA, SLE, SS with TB, are similar with the primary disease or other infection. It is recommended to conduct both TST and IGRA to help diagnose TB

Experimental study on mechanical properties of filling-bulk ce-menting combination body

In order to study the influence of caved rocks in the goaf on the backfilling body in the backfilling mining, uniaxial compression test are carried out on the backfilling body-cemented granular body combination with different granular heights, discrete element lithology and backfilling body strength. The uniaxial compression failure of the combination body specimen is monitored in real time by using the three-dimensional acoustic emission positioning technology. The deformation and failure corresponding to the AE events in the loading process is characterized by combining the time parameters of AE events with the starting time points of the four stages of the stress-strain curve. Based on this, the failure model for the interface of the combination body is established. The results show that the height of granular is negatively correlated with the strength of the combination body, and the uniaxial compressive strength of the combination body with the backfilling height ratio of 1:4 is only 55.0 % of that of the single backfilling body. The discrete element lithology and the strength of backfilling body are positively correlated with the strength of the combination body. Although high-strength backfilling body can improve the uniaxial compressive strength of the combination body, the higher the strength of filling body in the combination body, the more serious the strength reduction of the combination body. When the particle lithology in cemented bulk is siltstone with low strength, the uniaxial compressive strength of the combination body is only 42.9% of that of single combination body. The siltstone with smaller compressive strength will have a fracture plane due to shear failure during the failure, and the limestone with larger compressive strength can withstand shear load by using the shear strength of the granular particles. When the cementing matrix in the cemented granular fails or the particles in the cemented granular are broken, the interface of the backfilling body and the cemented granular undergoes non-uniform compression deformation, resulting in the stress concentration on the backfilling body on the interface damaged by the cemented granular, resulting in the shear failure of the upper backfilling body locally, and the failure of backfilling body is the contribution of both axial stress and non-uniform deformation of the interface

Efficient and ultra-stable perovskite light-emitting diodes

Perovskite light-emitting diodes (PeLEDs) have emerged as a strong contender for next-generation display and information technologies. However, similar to perovskite solar cells, the poor operational stability remains the main obstacle toward commercial applications. Here we demonstrate ultra-stable and efficient PeLEDs with extraordinary operational lifetimes (T50) of 1.0x10^4 h, 2.8x10^4 h, 5.4x10^5 h, and 1.9x10^6 h at initial radiance (or current densities) of 3.7 W/sr/m2 (~5 mA/cm2), 2.1 W/sr/m2 (~3.2 mA/cm2), 0.42 W/sr/m2 (~1.1 mA/cm2), and 0.21 W/sr/m2 (~0.7 mA/cm2) respectively, and external quantum efficiencies of up to 22.8%. Key to this breakthrough is the introduction of a dipolar molecular stabilizer, which serves two critical roles simultaneously. First, it prevents the detrimental transformation and decomposition of the alpha-phase FAPbI3 perovskite, by inhibiting the formation of lead and iodide intermediates. Secondly, hysteresis-free device operation and microscopic luminescence imaging experiments reveal substantially suppressed ion migration in the emissive perovskite. The record-long PeLED lifespans are encouraging, as they now satisfy the stability requirement for commercial organic LEDs (OLEDs). These results remove the critical concern that halide perovskite devices may be intrinsically unstable, paving the path toward industrial applications.Comment: This is a preprint of the paper prior to peer review. New and updated results may be available in the final version from the publishe

Cumulative live birth rates and birth outcomes after IVF/ICSI treatment cycles in young POSEIDON patients: A real-world study

ObjectiveThe aim of this study was to describe the cumulative live birth rates (CLBRs) of young women with or without low prognosis according to the POSEIDON criteria after IVF/ICSI cycles and to investigate whether the diagnosis of low prognosis increases the risk of abnormal birth outcomes.DesignRetrospective study.SettingA single reproductive medicine center.PopulationFrom January 2016 to October 2020, there were 17,893 patients (<35 years) involved. After screening, 4,105 women were included in POSEIDON group 1, 1,375 women were included in POSEIDON group 3, and 11,876 women were defined as non-POSEIDON.Intervention(s)Baseline serum AMH level was measured on the D2–D3 of menstrual cycle before IVF/ICSI treatment.Main outcome measure(s)Cumulative live birth rate (CLBR), birth outcomes.Result(s)After four stimulation cycles, the CLBRs in POSEIDON group 1, POSEIDON group 3, and non-POSEIDON group reached 67.9% (95% CI, 66.5%–69.3%), 51.9% (95% CI, 49.2%–54.5%), and 79.6% (95% CI, 78.9%–80.3%), respectively. There was no difference in gestational age, preterm delivery, cesarean delivery, and low birth weight infants between the three groups, but macrosomia was significantly higher in non-POSEIDON group, after adjusting for maternal age and BMI.Conclusion(s)The POSEIDON group shows lower CLBRs than the non-POSEIDON group in young women, while the risk of abnormal birth outcomes in the POSEIDON group will not increase

Single-Cell Transcriptomics of Proliferative Phase Endometrium: Systems Analysis of Cell–Cell Communication Network Using CellChat

The endometrium thickness increases by which endometrial angiogenesis occurs in parallel with the rapid growth of endometrium during the proliferative phase, which is orchestrated by complex cell–cell interactions and cytokine networks. However, the intercellular communication has not been fully delineated. In the present work, we studied the cell–cell interactome among cells of human proliferative phase endometrium using single-cell transcriptomics. The transcriptomes of 33,240 primary endometrial cells were profiled at single-cell resolution. CellChat was used to infer the cell–cell interactome by assessing the gene expression of receptor–ligand pairs across cell types. In total, nine cell types and 88 functionally related signaling pathways were found. Among them, growth factors and angiogenic factor signaling pathways, including EGF, FGF, IGF, PDGF, TGFb, VEGF, ANGPT, and ANGPTL that are highly associated with endometrial growth, were further analyzed and verified. The results showed that stromal cells and proliferating stromal cells represented cell–cell interaction hubs with a large number of EGF, PDGF incoming signals, and FGF outgoing signals. Endothelial cells exhibited cell–cell interaction hubs with a plenty of VEGF, TGFb incoming signals, and ANGPT outgoing signals. Unciliated epithelial cells, ciliated epithelial cells, and macrophages exhibited cell–cell interaction hubs with substantial EGF outgoing signals. Ciliated epithelial cells represented cell–cell interaction hubs with a large number of IGF and TGFb incoming signals. Smooth muscle cells represented lots of PDGF incoming signals and ANGPT and ANGPTL outgoing signals. This study deconvoluted complex intercellular communications at the single-cell level and predicted meaningful biological discoveries, which deepened the understanding of communications among endometrial cells