135 research outputs found
Robust H∞ filtering for uncertain 2-D continuous systems
This paper considers the problem of robust H∞ filtering for uncertain two-dimensional (2-D) continuous systems described by the Roesser state-space model. The parameter uncertainties are assumed to be norm-bounded in both the state and measurement equations. The purpose is the design of a 2-D continuous filter such that for all admissible uncertainties, the error system is asymptotically stable, and the H∞ norm of the transfer function, from the noise signal to the estimation error, is below a prespecified level. A sufficient condition for the existence of such filters is obtained in terms of a set of linear matrix inequalities (LMIs). When these LMIs are feasible, an explicit expression of a desired H∞ filter is given. Finally, a simulation example is provided to demonstrate the effectiveness of the proposed method. © 2005 IEEE.published_or_final_versio
XPA-Mediated Regulation of Global Nucleotide Excision Repair by Atr Is p53-Dependent and Occurs Primarily in S-Phase
Cell cycle checkpoints play an important role in regulation of DNA repair pathways. However, how the regulation occurs throughout the cell cycle remains largely unknown. Here we demonstrate that nucleotide excision repair (NER) is regulated by the ATR/p53 checkpoint via modulation of XPA nuclear import and that this regulation occurs in a cell cycle-dependent manner. We show that depletion of p53 abrogated the UV-induced nuclear translocation of XPA, while silencing of Chk1 or MAPKAP Kinase-2 (MK2) had no effect. Inhibition of p53 transcriptional activities and silencing of p53-Ser15 phosphorylation also reduced the damage-induced XPA nuclear import. Furthermore, in G1-phase cells the majority of XPA remained in the cytoplasm even after UV treatment. By contrast, while most of the XPA in S-phase cells was initially located in the cytoplasm before DNA damage, UV irradiation stimulated bulk import of XPA into the nucleus. Interestingly, the majority of XPA molecules always were located in the nucleus in G2-phase cells no matter whether the DNA was damaged or not. Consistently, the UV-induced Ser15 phosphorylation of p53 occurred mainly in S-phase cells, and removal of cyclobutane pyrimidine dimers (CPDs) was much more efficient in S-phase cells than in G1-phase cells. Our results suggest that upon DNA damage in S phase, NER could be regulated by the ATR/p53-dependent checkpoint via modulation of the XPA nuclear import process. In contrast, the nuclear import of XPA in G 1 or G 2 phase appears to be largely independent of DNA damage and p53
Nucleated red blood cells as a novel biomarker in the diagnosis and prediction of sepsis severity in children
IntroductionSepsis is a vitally serious disease leading to high mortality. Nucleated red blood cells (NRBCs) are present in some noninfectious diseases, but the relationship between NRBCs and sepsis in children remains unknown. The purpose of this study was to compare the clinical characteristics and outcomes of sepsis with positive NRBCs and negative NRBCs in children, and to further explore whether the count of NRBCs has a relationship with the severity of sepsis.MethodsWe enrolled children with sepsis who were admitted to the Children’s Hospital of Chongqing Medical University between January 2020 and December 2022. The children’s clinical data, laboratory data and outcomes were recorded and analyzed.ResultsOne hundred and fifteen children met the inclusion criteria in our study. Compared to negative NRBCs patients, the C-reactive protein, alanine transaminase, urea nitrogen values, mortality rate and length of hospitalization were found to be significantly increased, while platelet counts, and hemoglobin were significantly decreased in sepsis patients with positive NRBC (P < 0.05). Receiver operating characteristic (ROC) curves analysis showed that the optimal cutoff value of the NRBC count in the diagnosis of severe sepsis was 3, with a sensitivity of 87.5% and specificity of 94.9%. The area under the ROC curve was 0.877 (95% CI: 0.798-0.957).DiscussionThese findings demonstrated that NRBC count has the potential to be a biomarker for the diagnosis of sepsis in children, especially an NRBC count greater than 3, which may predict the severity and poor prognosis in children suffering from sepsis
Transfer of Bone-Marrow-Derived Mesenchymal Stem Cells Influences Vascular Remodeling and Calcification after Balloon Injury in Hyperlipidemic Rats
Bone-marrow-derived mesenchymal stem cells (BM-MSCs) were found to markedly increase atherosclerotic lesion size. The aim of this paper was to investigate whether BM-MSCs contribute to vascular remodeling and calcification after balloon injury in hyperlipidemic rats. Labeled BM-MSCs were found in the lesion of hyperlipidemic rats after balloon injury. Comparing injury group, transferred BM-MSCs significantly triggered vascular negative remodeling, characterized by the changes of remodeling index (0.628 ± 0.0293 versus 0.544 ± 0.0217), neointimal area (0.078 ± 0.015 mm2 versus 0.098 ± 0.019 mm2), PCNA index (23.91 ± 6.59% versus 43.11 ± 5.31%), and percentage of stenosis (18.20 ± 1.09% versus 30.58 ± 1.21%). Apparent vascular calcification was detected in medial layers at 6 weeks after balloon angioplasty, which may be associated with upregulation of bone morphogenetic protein-2 (BMP-2). Our data indicated that unselected BM-MSCs transfer may induce vascular remodeling and calcification after balloon injury in hyperlipidemic rats
深部軟岩坑道用ハイコンベックス・ストリップボルトを用いた複合支保技術に関する研究
Based on the systematic analysis of mechanical characteristics for deep roadway excavated in soft strata, the high convex strip-bolting support technology was put forward, and a numerical analysis was carried out by FLAC3D. The process of general bolting support and high convex strip-bolting support of deep soft rock roadway were simulated. The results indicate that the convex bed of strip-band can adapt to large deformation of high pre-stressed bolting, and the high strength and high rigidity of strip can bear large axial force and moment of flexion. In addition, bolting and anchoring combined support can control the deformation of rock masses by transferring the strength of deep strata, and bolt-grouting can form stress-relief region in deep and generates high strength invert arch at shallow which can afford some support resistances. A case study is also presented and the results of field measurement show that the new support system is suitable for roadways excavated in weak rocks.特集 : 「資源、新エネルギー、環境、防災研究国際セミナー
The Special Neuraminidase Stalk-Motif Responsible for Increased Virulence and Pathogenesis of H5N1 Influenza A Virus
The variation of highly pathogenic avian influenza H5N1 virus results in gradually increased virulence in poultry, and human cases continue to accumulate. The neuraminidase (NA) stalk region of influenza virus varies considerably and may associate with its virulence. The NA stalk region of all N1 subtype influenza A viruses can be divided into six different stalk-motifs, H5N1/2004-like (NA-wt), WSN-like, H5N1/97-like, PR/8-like, H7N1/99-like and H5N1/96-like. The NA-wt is a special NA stalk-motif which was first observed in H5N1 influenza virus in 2000, with a 20-amino acid deletion in the 49th to 68th positions of the stalk region. Here we show that there is a gradual increase of the special NA stalk-motif in H5N1 isolates from 2000 to 2007, and notably, the special stalk-motif is observed in all 173 H5N1 human isolates from 2004 to 2007. The recombinant H5N1 virus with the special stalk-motif possesses the highest virulence and pathogenicity in chicken and mice, while the recombinant viruses with the other stalk-motifs display attenuated phenotype. This indicates that the special stalk-motif has contributed to the high virulence and pathogenicity of H5N1 isolates since 2000. The gradually increasing emergence of the special NA stalk-motif in H5N1 isolates, especially in human isolates, deserves attention by all
Historical and contemporary management of infantile hemangiomas: a single-center experience
Objective: This study explores the 22-year evolution of Infantile Hemangiomas (IHs) treatment strategies at a single-center hospital, aiming to establish an individualized IHs management protocol.Methods: Retrospective review of IHs infants 2000–2022 at the Department of Plastic Surgery, Jiangxi Provincial Children’s Hospital.Results: In our study of 27,513 IHs cases, 72.2% were female, with the median age at first hospital visit being 25 days. The majority of cases had localized and superficial lesions primarily on the head, face, and neck (67.5%). Ulceration rates fell from 21.1% to 12.6% with the introduction of propranolol. Management strategies have shifted over time, with the proportion of cases undergoing expectant management dropping from 32.9% to 12.4%. Since 2008, 26.1% of patients were treated with oral propranolol, largely replacing corticosteroids. Topical β-blockers have been used in 12.1% of cases, leading to a reduction in local injection therapy from 20.8% to 13.2%. Laser therapy, introduced in 2016, has been used in 13.8% of cases, while surgical excision has dropped from 25.0% to 8.5% due to alternative treatment options. Combination therapy was used in 8.8% of cases post-2015, indicating a rising trend. Drawing from the evolution of IHs management strategies, an individualized protocol for the management of IHs was successfully established.Conclusion: Treatment for IHs has evolved over recent decades, with less invasive medical interventions increasingly replacing more invasive methods. Furthermore, a personalized treatment protocol established in this study could boost the cure rate of IHs while minimizing potential side effects and complications
Unravelling surface and interfacial structures of a metal–organic framework by transmission electron microscopy
Metal-organic frameworks (MOFs) are crystalline porous materials with designable topology, porosity and functionality, having promising applications in gas storage and separation, ion conduction and catalysis. It is challenging to observe MOFs with transmission electron microscopy (TEM) due to the extreme instability of MOFs upon electron beam irradiation. Here, we use a direct-detection electron-counting camera to acquire TEM images of the MOF ZIF-8 with an ultralow dose of 4.1 electrons per square ångström to retain the structural integrity. The obtained image involves structural information transferred up to 2.1 Å, allowing the resolution of individual atomic columns of Zn and organic linkers in the framework. Furthermore, TEM reveals important local structural features of ZIF-8 crystals that cannot be identified by diffraction techniques, including armchair-type surface terminations and coherent interfaces between assembled crystals. These observations allow us to understand how ZIF-8 crystals self-assemble and the subsequent influence of interfacial cavities on mass transport of guest molecules
Different Effects of Total Bilirubin on 90-Day Mortality in Hospitalized Patients With Cirrhosis and Advanced Fibrosis: A Quantitative Analysis
Introduction: Total bilirubin (TB) is a major prognosis predictor representing liver failure in patients with acute on chronic liver failure (ACLF). However, the cutoff value of TB for liver failure and whether the same cutoff could be applied in both cirrhotic and non-cirrhotic patients remain controversial. There is a need to obtain the quantitative correlation between TB and short-term mortality via evidence-based methods, which is critical in establishing solid ACLF diagnostic criteria.Methods: Patients hospitalized with cirrhosis or advanced fibrosis (FIB-4 > 1.45) were studied. TB and other variables were measured at baseline. The primary outcome was 90-day transplantation-free mortality. Multi-variable Cox proportional hazard model was used to present the independent risk of mortality due to TB. Generalized additive model and second derivate (acceleration) were used to plot the “TB-mortality correlation curves.” The mathematical (maximum acceleration) and clinical (adjusted 28-day transplantation-free mortality rate reaching 15%) TB cutoffs for liver failure were both calculated.Results: Among the 3,532 included patients, the number of patients with cirrhosis and advanced fibrosis were 2,592 and 940, respectively, of which cumulative 90-day mortality were 16.6% (430/2592) and 7.4% (70/940), respectively. Any increase of TB was found the independent risk factor of mortality in cirrhotic patients, while only TB >12 mg/dL independently increased the risk of mortality in patients with advanced fibrosis. In cirrhotic patients, the mathematical TB cutoff for liver failure is 14.2 mg/dL, with 23.3% (605/2592) patients exceeding it, corresponding to 13.3 and 25.0% adjusted 28- and 90-day mortality rate, respectively. The clinical TB cutoff for is 18.1 mg/dL, with 18.2% (471/2592) patients exceeding it. In patients with advanced fibrosis, the mathematical TB cutoff is 12.1 mg/dL, 33.1% (311/940) patients exceeding it, corresponding to 2.9 and 8.0% adjusted 28- and 90-day mortality rate, respectively; the clinical TB cutoff was 36.0 mg/dL, 1.3% (12/940) patients above it.Conclusion: This study clearly demonstrated the significantly different impact of TB on 90-day mortality in patients with cirrhosis and advanced fibrosis, proving that liver failure can be determined by TB alone in cirrhosis but not in advanced fibrosis. The proposed TB cutoffs for liver failure provides solid support for the establishment of ACLF diagnostic criteria
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