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Comparison between SARS-CoV-2 positive and negative pneumonia in children:A retrospective analysis at the beginning of the pandemic

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World Journal of Experimental Medicine 2022年第2期12卷 26-35页

作者： Adil Zhamankulov Rafail Rozenson Marina Morenko Ulzhan Akhmetova Alina Tyo dimitri Poddighe Department of Children's diseases Astana Medical UniversityFirst Children's Municipal HospitalNur-Sultan 010000Kazakhstan Clinical Academic Department of Pediatrics National Research Center for Maternal and Child HealthUniversity Medical CenterNur-Sultan 010000Kazakhstan

BACKGROUND Even though coronavirus 2019 disease(COVID-19)clinical course in children is much milder than in adults,pneumonia can occur in the pediatric population as ***,we reported a single-center pediatric case series of COVID-19 from Kazakhstan during the first wave of *** To analyze the main clinical and laboratory aspects in severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)positive and negative children diagnosed with *** This is a retrospective analysis of 54 children,who were medically assessed as close contacts of COVID-19 adults in their family setting,between June and September *** children were all hospitalized:We compared the clinical and laboratory characteristics of children affected with pneumonia in the presence(group 1)or absence(group 2)of SARS-CoV-2 *** Overall,the main clinical manifestations at the admission were fever,cough,loss of appetite,fatigue/weakness,nasal congestion and/or rhinorrhea,and *** on the SARS-CoV-2 polymerase chain reaction(PCR)test,24 positive children with pneumonia(group 1)and 20 negative children with pneumonia(group 2)were identified;10 positive children did not show any radiological findings of *** significant differences were found between the two pneumonia study groups for any clinical and laboratory parameters,except for C-reactive protein(CRP).Of course,both pneumonia groups showed increased CRP values;however,the COVID-19 pneumonia group 1 showed a significantly higher increase of CRP compared to group *** In our case series of children assessed for SARS-CoV-2 infection based on contact tracing,the acute inflammatory response and,in detail,CRP increase resulted to be more pronounced in COVID-19 children with pneumonia than in children with SARS-CoV-2-unrelated ***,because of multiple limitations of this study,larger,controlled and more complete clinical studies are needed to verify this finding.

关键词： Pediatric COVID-19 SARS-CoV-2 Pneumonia C-reactive protein Chest X-ray Inflammatory parameters

Fourier time spectral method for subsonic and transonic flows

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Acta Mechanica Sinica 2016年第3期32卷 380-396页

作者： Lei Zhan Feng Liu dimitri Papamoschou School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China Department of Mechanical and Aerospace Engineering University of CaliforniaIrvineCA 92697USA

The time accuracy of the exponentially accurate Fourier time spectral method（TSM） is examined and compared with a conventional 2nd-order backward difference formula（BDF） method for periodic unsteady flows. In particular, detailed error analysis based on numerical computations is performed on the accuracy of resolving the local pressure coefficient and global integrated force coefficients for smooth subsonic and non-smooth transonic flows with moving shock waves on a pitching airfoil. For smooth subsonic flows, the Fourier TSM method offers a significant accuracy advantage over the BDF method for the prediction of both the local pressure coefficient and integrated force coefficients. For transonic flows where the motion of the discontinuous shock wave contributes significant higherorder harmonic contents to the local pressure fluctuations,a sufficient number of modes must be included before the Fourier TSM provides an advantage over the BDF *** Fourier TSM, however, still offers better accuracy than the BDF method for integrated force coefficients even for transonic flows. A problem of non-symmetric solutions for symmetric periodic flows due to the use of odd numbers of intervals is uncovered and analyzed. A frequency-searching method is proposed for problems where the frequency is not known a priori. The method is tested on the vortex shedding problem of the flow over a circular cylinder.

关键词： Fourier time spectral method(TSM) Pitching airfoil Transonic flow Non-symmetric solution Computational efficiency Vortex shedding flow Frequency search

Measuring turbulence in a circulating fluidized bed using PIV techniques

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Particuology 2011年第6期9卷 572-588页

作者： Mayank Kashyap Benjapon Chalermsinsuwan dimitri Gidaspow Department of Chemical and Biological Engineering Illinois Institute of Technology Fuel Research Center Department of Chemical Technology Faculty of Science Chulalongkorn University Center of Excellence for Petroleum Petrochemicals and Advanced Materials Chulalongkorn University

This study utilized the particle image velocimetry （P1V） technique, non-invasively near the wall, in the developing region, for the measurements of laminar and turbulent properties during circulation of Geldart B type particles in the U.S. Department of Energy （DOE） National Energy Technology Laboratory （NETL） riser. A novel method was used to measure axial and radial laminar and turbulent solids dispersion coefficients using autocorrelation technique. The instantaneous and hydrodynamic velocities for the solid phase were measured simultaneously in the axial and radial directions using a CCD camera, with the help of a colored rotating transparency. The measured properties, such as laminar and Reynolds stresses, laminar and turbulent granular tempera- tures, laminar and turbulent dispersion coefficients and energy spectra exhibited anisotropy. The mixing in the riser was on the level of clusters. The total granular temperatures were in reasonable agreement with the literature values. However, the axial and radial solids dispersion coefficients measured near the wall were slightly lower than the radially averaged values in the literature.

关键词： Particle image velocimetry (PIV) Dispersion coefficient Autocorrelation Turbulence Anisotrnpy

Active gastrointestinal bleeding:Use of hemostatic forceps beyond endoscopic submucosal dissection

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World Journal of Gastroenterology 2010年第16期16卷 2061-2064页

作者： dimitri Coumaros Niki Tsesmeli Department of Hepatogastroenterology University Hospital of Strasbourg

To the best of our knowledge,this is the f irst report of the application of hemostatic forceps in active gastrointestinal(GI) bleeding that is not related to endoscopic submucosal *** 86-year-old woman with chronic intake of low-dose aspirin had a Dieulafoy's lesion of the third duodenal *** control with epinephrine injection was unsuccessful.A 60-year-old man presented with a bleeding ulcer in the duodenal *** days after combined endotherapy,he had recurrent bleeding from two minimal lesions in the same location.A 66-year-old woman under combined antithrombotic treatment was referred to us for chronic GI bleeding of unexplained *** revealed active diverticular bleeding in the second duodenal portion.A 61-year-old woman underwent endoscopic mucosal resection of superficial gastric adenocarcinoma,which was complicated with immediate *** all cases,the blood was washed out using a water-jet-equipped,single-channel gastroscope with a large working *** bleeding points were pinched and retracted with hemostatic *** electrocoagulation was performed using an electrosurgical current *** was *** complications *** conclusion,hemostatic forceps may be an effective as well as safe alternative approach for active GI bleeding of various origins.

关键词： Hemostasis Forceps Blood coagulation Hemorrhage Endoscopic submucosal dissection

Acute acalculous cholecystitis in children

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World Journal of Gastroenterology 2018年第43期24卷 4870-4879页

作者： dimitri Poddighe Vitaliy Sazonov Department of Medicine School of MedicineNazarbayev University Pediatric Intensive Care Unit UMC National Research Center for Mother and Child Health

Acute acalculous cholecystitis(AAC) is the inflammatory disease of the gallbladder in the absence of gallstones. AAC is estimated to represent at least 50% to 70% of all cases of acute cholecystitis during childhood. Although this pathology was originally described in critically ill or post-surgical patients, most pediatric cases have been observed during several infectious diseases. In addition to cases caused by bacterial and parasitic infections, most pediatric reports after 2000 described children developing AAC during viral illnesses(such as Epstein-Barr virus and hepatitis A virus infections). Moreover, some pediatric cases have been associated with several underlying chronic diseases and, in particular, with immune-mediated disorders. Here, we review the epidemiological aspects of pediatric AAC, and we discuss etiology, pathophysiology and clinical management, according to the cases reported in the medical literature.

关键词：胆汁孩子病毒感染传染疾病 AAC 流行病学案例儿科

EPR spectroscopy of whole blood and blood components:can we diagnose abnormalities?

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The Journal of Biomedical Research 2021年第4期35卷 294-300页

作者： dimitri A.Svistunenko School of Life Sciences University of EssexColchesterEssex CO43SQUK.

This mini-review gives a brief account of the emergence of the electron paramagnetic resonance(EPR)spectroscopy in the second half of the 20th century and reports the continuous wave EPR spectroscopy studies on human and animal *** question posed by this review is whether the EPR spectroscopy in the form it appeared 70 years ago is still able to provide useful information about different pathological conditions in humans,particularly in the area of diagnosis.

关键词： EPR spectroscopy biological tissues paramagnetic metals protein free radicals human blood animal blood

Celiac Disease in Asia beyond the Middle East and Indian subcontinent:Epidemiological burden and diagnostic barriers

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World Journal of Gastroenterology 2021年第19期27卷 2251-2256页

作者： dimitri Poddighe Diyora Abdukhakimova Department of Medicine School of MedicineNazarbayev UniversityNur-Sultan 010000Kazakhstan Clinical Academic Department of Pediatrics Research Center for Maternal and Child HealthUniversity Medical CenterNur-Sultan 010000Kazakhstan

Celiac Disease(CD)had been considered uncommon in Asia for a long ***,several studies suggested that,in the Indian subcontinent and Middle East countries,CD is present and as prevalent as in Western *** these Asian regions,the information about the epidemiology of CD is still lacking or largely incomplete for different and variable ***,we discuss the epidemiological aspects and the diagnostic barriers in several Asian regions including China,Japan,Southeast Asia and Russia/Central *** some of those regions,especially Russia and Central Asia,the prevalence of CD is very likely to be *** factors may,to a different extent,contribute to CD underdiagnosis(and,thus,underestimation of its epidemiological burden),including the poor disease awareness among physicians and/or patients,limited access to diagnostic resources,inappropriate use or interpretation of the serological tests,absence of standardized diagnostic and endoscopic protocols,and insufficient expertise in histopathological interpretation.

关键词： Celiac disease Epidemiology Prevalence Asia China Japan Russia Central Asia HLA-DQB1 Diagnostic barriers

Approximate policy iteration:a survey and somenew methods

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控制理论与应用（英文版） 2011年第3期9卷 310-335页

作者： dimitri P.BERTSEKAS Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology

We consider the classical policy iteration method of dynamic programming(DP),where approximations and simulation are used to deal with the curse of *** survey a number of issues:convergence and rate of convergence of approximate policy evaluation methods,singularity and susceptibility to simulation noise of policy evaluation,exploration issues,constrained and enhanced policy iteration,policy oscillation and chattering,and optimistic and distributed policy *** discussion of policy evaluation is couched in general terms and aims to unify the available methods in the light of recent research developments and to compare the two main policy evaluation approaches:projected equations and temporal differences(TD),and *** the context of these approaches,we survey two different types of simulation-based algorithms:matrix inversion methods,such as least-squares temporal difference(LSTD),and iterative methods,such as least-squares policy evaluation(LSPE) and TD(λ),and their scaled *** discuss a recent method,based on regression and regularization,which recti?es the unreliability of LSTD for nearly singular projected Bellman *** iterative version of this method belongs to the LSPE class of methods and provides the connecting link between LSTD and *** discussion of policy improvement focuses on the role of policy oscillation and its effect on performance *** illustrate that policy evaluation when done by the projected equation/TD approach may lead to policy oscillation,but when done by aggregation it does *** implies better error bounds and more regular performance for aggregation,at the expense of some loss of generality in cost function representation *** aggregation provides the connecting link between projected equation/TD-based and aggregation-based policy evaluation,and is characterized by favorable error bounds.

关键词： Dynamic programming Policy iteration Projected equation Aggregation Chattering Regularization

Model Predictive Control for Discrete and Continuous Timed Petri Nets

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International Journal of Automation and computing 2018年第1期15卷 25-38页

作者： Marwa Taleb Edouard Leclercq dimitri Lefebvre Laboratory GREAH University of Le Havre

The goal of this paper is to propose a unique control method that permits the evolution of both timed continuous Petri net （TCPN） and T-timed discrete Petri net （T-TDPN） from an initial state to a desired one. Model predictive control （MPC） is a robust control scheme against perturbation and a consistent real-time constraints method. Hence, the proposed approach is studied using the MPC. However, the computational complexity may prevent the use of the MPC for large systems and for large prediction horizons. Then, the proposed approach provides some new techniques in order to reduce the high computational complexity; among them one is taking constant control actions during the prediction.

关键词： Model predictive control timed continuous Petri net (TCPN) T-timed discrete Petri net (T-TDPN) fluidification optimization constant control.