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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： Acute acalculous cholecystitis Children Viral biliary disorders

Effectiveness of Bilateral Pulmonary Artery Banding in Patients with Hypoplastic Left Heart Syndrome and Congenital Heart Defects with a Functional Single Ventricle: A Single-Center Retrospective Study

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Congenital Heart Disease 2022年第3期17卷 365-374页

作者： vitaliy Suvorov Vladimir Zaitcev Karolina Andrzejczyk Saint Petersburg State Pediatric Medical University Saint-PetersburgRussia Academisch Medisch Centrum Universiteit van Amsterdam AmsterdamNetherlands

Background:Bilateral banding of the branches of the pulmonary artery in patients with hypoplastic left heart syndrome(HLHS)and other duct dependent critical neonatal heart malformations can significantly reduce the incidence of severe complications in the postoperative period,especially in severely unstable *** our study we compared different surgical techniques of bilateral pulmonary artery banding(PAB)in respect to their success in balancing systemic and pulmonary blood ***:We included 44 neonates with a HLHS and congenital heart diseases(CHD)with a functional single ventricle underwent a hybrid operation:bilateral PAB and patent ductus arteriosus *** hybrid surgery for method No.1 is performed as a one-stage procedure,together with patent ductus arteriosus(PDA)*** median sternotomy,two Gore-Tex 1–2 mm wide bands with a diameter of 3–3.5 mm are *** we apply method No.2 then the thread is used to create *** No.3 is distinguished by intraoperative assessment of blood flow at the site of narrowing of the branches of the pulmonary artery and optional stenting of the *** cuff for banding is made of Gore-Tex *** when applying method Nos.1 and 2 is assessed by the change in invasive blood pressure and oxygen saturation after narrowing of the branches of the pulmonary ***,with these techniques PDA stenting by inserting the introducer via pulmonary artery trunk is ***:HLHS with mitral or aortic valve atresia or both was present in 19 patients(43.1%),with severe left heart obstruction resulting in PDA dependent systemic circulation in 16 babies(36.4%).CHD with single ventricle physiology occurred in 9 patients(20.5%).14 babies(31.8%)undergo the procedure following the method No.1,8 patients(18.2%)method No.2 and 22 patients(50%)method ***/Qs=1/1 was achieved in 30 patients(30/44,68.1%):as a result of the method No.1 was achieved in 5 patients(5/14,35.7%),method No.2 in 4 patien

关键词： Bilateral banding hybrid Norwood procedure pulmonary banding hybrid approach HLHS surgery single ventricle

Optimization of Artificial Viscosity in Production Codes Based on Gaussian Regression Surrogate Models

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Communications on Applied Mathematics and Computation 2024年第3期6卷 1521-1550页

作者： vitaliy Gyrya Evan Lieberman Mark Kenamond Mikhail Shashkov Applied Mathematics and Plasma Physics Theoretical DivisionMail Stop B284Los Alamos National LaboratoryLos AlamosNM 87545USA Continuum Models and Numerical Methods Group X-Computational Physics DivisionMail Stop F644Los Alamos National LaboratoryLos AlamosNM 87545USA Lagrangian Codes Group X-Computational Physics DivisionMail Stop T086Los Alamos National LaboratoryLos AlamosNM 87545USA

To accurately model flows with shock waves using staggered-grid Lagrangian hydrodynamics, the artificial viscosity has to be introduced to convert kinetic energy into internal energy, thereby increasing the entropy across shocks. Determining the appropriate strength of the artificial viscosity is an art and strongly depends on the particular problem and experience of the researcher. The objective of this study is to pose the problem of finding the appropriate strength of the artificial viscosity as an optimization problem and solve this problem using machine learning (ML) tools, specifically using surrogate models based on Gaussian Process regression (GPR) and Bayesian analysis. We describe the optimization method and discuss various practical details of its implementation. The shock-containing problems for which we apply this method all have been implemented in the LANL code FLAG (Burton in Connectivity structures and differencing techniques for staggered-grid free-Lagrange hydrodynamics, Tech. Rep. UCRL-JC-110555, Lawrence Livermore National Laboratory, Livermore, CA, 1992, 1992, in Consistent finite-volume discretization of hydrodynamic conservation laws for unstructured grids, Tech. Rep. CRL-JC-118788, Lawrence Livermore National Laboratory, Livermore, CA, 1992, 1994, Multidimensional discretization of conservation laws for unstructured polyhedral grids, Tech. Rep. UCRL-JC-118306, Lawrence Livermore National Laboratory, Livermore, CA, 1992, 1994, in FLAG, a multi-dimensional, multiple mesh, adaptive free-Lagrange, hydrodynamics code. In: NECDC, 1992). First, we apply ML to find optimal values to isolated shock problems of different strengths. Second, we apply ML to optimize the viscosity for a one-dimensional (1D) propagating detonation problem based on Zel’dovich-von Neumann-Doring (ZND) (Fickett and Davis in Detonation: theory and experiment. Dover books on physics. Dover Publications, Mineola, 2000) detonation theory using a reactive burn model. We compare re

关键词： Optimization Artificial viscosity Gaussian regression surrigate model

Plural interactions of space charge wave harmonics during the development of two-stream instability

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Chinese Physics B 2015年第9期24卷 332-336页

作者： Victor Kulish Alexander Lysenko Michael Rombovsky vitaliy Koval Iurii Volk National Aviation University Department of Theoretical Physics Sumy State University Department of General and Theoretical Physics

We construct a cubically nonlinear theory of plural interactions between harmonics of the growing space charge wave（SCW） during the development of the two-stream instability. It is shown that the SCW with a wide frequency spectrum is formed when the frequency of the first SCW harmonic is much lower than the critical frequency of the two-stream *** SCW has part of the spectrum in which higher harmonics have higher amplitudes. We analyze the dynamics of the plural harmonic interactions of the growing SCW and define the saturation harmonic levels. We find the mechanisms of forming the multiharmonic SCW for the waves with frequencies lower than the critical frequency and for the waves with frequencies that exceed the critical frequency.

关键词： two-stream instability three-wave parametric resonances space charge wave free-electron laser

A New Three-Dimensional(3D)Printing Prepress Algorithm for Simulation of Planned Surgery for Congenital Heart Disease

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Congenital Heart Disease 2023年第5期18卷 491-505页

作者： vitaliy Suvorov Olga Loboda Maria Balakina Igor Kulczycki Department of Surgical Diseases of Children Saint Petersburg State Pediatric Medical UniversitySaint PetersburgRussia Higher School of Theoretical Mechanics Peter the Great Saint Petersburg Polytechnic UniversitySaint PetersburgRussia

Background:Three-dimensional printing technology may become a key factor in transforming clinical practice and in significant improvement of treatment *** introduction of this technique into pediatric cardiac surgery will allow us to study features of the anatomy and spatial relations of a defect and to simulate the optimal surgical repair on a printed model in every individual ***:We performed the prospective cohort study which included 29 children with congenital heart *** hearts and the great vessels were modeled and printed *** of the same cardiac areas were taken in the same planes and points at multislice computed tomography images(group 1)and on printed 3D models of the hearts(group 2).Pre-printing treatment of the multislice computed tomography data and 3D model preparation were performed according to a newly developed ***:The measurements taken on the 3D-printed cardiac models and the tomographic images did not differ significantly,which allowed us to conclude that the models were highly accurate and *** new algorithm greatly simplifies and speeds up the preparation of a 3D model for printing,while maintaining high accuracy and level of ***:The 3D-printed models provide an accurate preoperative assessment of the anatomy of a defect in each *** new algorithm has several important advantages over other available *** enable the development of customized preliminary plans for surgical repair of each specific complex congenital heart disease,predict possible issues,determine the optimal surgical tactics,and significantly improve surgical outcomes.

关键词： 3D printing imaging in cardiac surgery congenital heart disease modelling in cardiac surgery pediatric cardiology algorithmic modelling of the heart medical imaging 3D modelling

The impact of surgeon choices on costs associated with uncomplicated minimally invasive colectomy:you are not as important as you think

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Gastroenterology Report 2018年第2期6卷 108-113,I0002页

作者： John Tillou Deborah Nagle vitaliy Poylin Thomas Cataldo Division of Colon and Rectal Surgery Department of SurgeryBeth Israel Deaconess Medical CenterBostonMAUSA

Background:There is increasing public discussion about the escalating cost of healthcare in *** are no published data regarding the contribution of individual surgeons’choices on the cost of uncomplicated minimally invasive ***:A review of a hospital cost-accounting database of the direct costs related to the index operation and postoperative care of all patients who underwent elective minimally invasive segmental colectomy over a 1-year period was ***:A total of 111 cases were enrolled in this study,18 of which were performed *** average direct cost after minimally invasive colectomy was$*** cost of robotic colectomy was 53%greater than laparoscopic($7806 vs$5096,p<0.001).There was no statistically significant difference in overall costs among laparoscopic cases performed by three surgeons($5099 vs$5108 vs$5055,p¼0.987).Average operating room supply costs among the three surgeons were$1236,$1105 and$1030,respectively(p¼0.067),with a standard deviation of$328(6.4%of overall cost).Conclusions:No significant difference in overall costs between surgeons was demonstrated despite varied training,experience levels and operative *** costs are relatively institutionally fixed and minimally influenced by variations in individual surgeon preferences.

关键词： cost minimally invasive colectomy laparoscopy individual surgeon

Low temperature microwave-assisted vs conventional pyrolysis of various biomass feedstocks

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Journal of Natural Gas Chemistry 2012年第3期21卷 270-274页

作者： Peter Shuttleworth vitaliy Budarin Mark Gronnow James H.Clark Rafael Luque Green Chemistry Centre of Excellence University of YorkHeslingtonYO10 5DD YorkUK Departamento de Química Orgnica Universidad de CórdobaCampus de Excelencia Agroalimentario ceiA3Edif icio Marie Curie(C-3)Ctra Nnal IVKm 396E-14014CórdobaSpain

A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste residues. Microwave pyrolysis was found to efficiently deliver comparable evolution of bio-gases in the system as compared with conventional pyrolysis at significantly reduced temperatures （120-180 ℃vs 250-400 ℃）. The gas obtained from microwave-assisted pyrolysis was found to contain CO2, CH4 and CO as major components as well

关键词： microwave-assisted pyrolysis biomass valorisation gas production

Structural Changes and Electrodynamic Effects in Polymers under Fast Uniaxial Compression

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Chinese Journal of Polymer Science 2021年第5期39卷 601-609,I0007页

作者： Aleksey.I.Aleksandrov Ivan A.Aleksandrov vitaliy G.Shevchenko Aleksandr N.Ozerin N.S.Enikolopov Institute of Synthetic Polymeric Materials RAS 117393 Moscow Profsoyuznaya70 Russian Federation

Rheological explosion in polymers under uniaxial compression in an open volume occurs at the end of continuous rapid plastic deformation after several stages of *** types of polymers were chosen for this study:brittle glassy amorphous polystyrene and thermoplastic semi-crystalline *** pulses were detected during explosion,and their spectra were analyzed with two models.X-ray diffraction methods were used to investigate changes in the structure and morphology of polymers during deformation and rheological *** pores appear in polymer in this process,and their shape and size distribution were derived from X-ray *** main reason for the formation of pores in polymer samples in rheological explosion experiments is the intense microshifts in the polymer volume under the action of high applied pressure.

关键词： Polystyrene Polypropylene X-ray Mechanical properties Compression

Emergency Hybrid Correction in a Newborn with Critical Aortic Valve Stenosis with Acute Pulmonary Edema in the First Hour after Birth

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Congenital Heart Disease 2023年第1期18卷 57-65页

作者： vitaliy Suvorov Vladimir Zaitsev Nikolay Pilyugov Olga Tereshenko Michail Komissarov Saint Petersburg State Pediatric Medical University Saint-PetersburgRussia

Critical aortic valve stenosis in newborns is the cause of a severe clinical condition with the onset of symptoms during first hours after *** present a clinical case of a successful surgical correction of a critical aortic stenosis using a hybrid method applied in a newborn during the first day of *** infant was diagnosed with a hypoplastic left heart complex with an intact atrial septum(aortic and mitral valves stenosis variant),that led to the cardiogenic shock and acute pulmonary *** procedure included bilateral banding of the pulmonary artery branches and atrioseptostomy with stenting of the interatrial *** surgery was performed through a median sternotomy.

关键词： Critical aortic valve stenosis hybrid correction hybrid Norwood bilateral banding hybrid Norwood procedure acute pulmonary edema intact atrial septum hypoplastic left heart complex