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Endoscopic management of biliary strictures after liver transplantation

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World Journal of Gastroenterology 2009年第30期15卷 3725-3733页

作者： Emmanuelle d Williams Peter v draganov division of Gastroenterology University of FloridaGainesvilleFL 32610-0214United States

Bile duct strictures remain a major source of morbidity after orthotopic liver transplantation (OLT). Biliary strictures are classifi ed as anastomotic or non-anastomotic strictures according to location and are defi ned by distinct clinical behaviors. Anastomotic strictures are localized and short. The outcome of endoscopic treatment for anastomotic strictures is excellent. Nonanastomotic strictures often result from ischemic and immunological events, occur earlier and are usually multiple and longer. They are characterized by a far less favorable response to endoscopic management, higher recurrence rates, graft loss and need for retransplantation. Living donor OLT patients present a unique set of challenges arising from technical factors, and stricture risk for both recipients and donors. Endoscopic treatment of living donor OLT patients is less promising. Current endoscopic strategies for biliary strictures after OLT include repeated balloon dilations and placement of multiple side-by-side plastic stents. Lifelong surveillance is required in all types of strictures. despite improvements in incidence and long term outcomes with endoscopic management, and a reduced need for surgical treatment, the impact of strictures on patients after OLT is signifi cant. Future considerations include new endoscopic technologies and improved stents, which could potentially allow for a decreased number of interventions, increased intervals before retreatment, and decreased reliance on percutaneous and surgical modalities. This review focuses on the role of endoscopy in biliary strictures, one of the most common biliary complications after OLT.

关键词： Anastomotic strictures Bile duct diseases Endoscopic retrograde cholangiopancreatography Orthotopic liver transplantation Surgical anastomosis

Pancreatic fistula after pancreatectomy:Evolving definitions,preventive strategies and modern management

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World Journal of Gastroenterology 2008年第38期14卷 5789-5796页

作者： Shailesh v Shrikhande Melroy A d'Souza department of GI and HPB Surgical Oncology Tata Memorial HospitalMumbai 400-012 India

Pancreatic resection is the treatment of choice for pancreatic malignancy and certain benign pancreatic disorders. However, pancreatic resection is technically a demanding procedure and whereas mortality after a pancreaticoduodenectomy is currently d high-volume centers, post-operative morbidity is considerable, about 30%-50%. At present, the single most significant cause of morbidity and mortality after pancreatectomy is the development of pancreatic leakage and fistula (PF). The occurrence of a PF increases the length of hospital stay and the cost of treatment, requires additional investigations and procedures, and can result in life-threatening complications. There is no universally accepted definition of PF that would allow standardized reporting and proper comparison of outcomes between different centers. However, early recognition of a PF and prompt institution of appropriate treatment is critical to the prevention of potentially devastating consequences. The present article, reviews the evolution of post resection pancreatic fistula as a concept, and discusses evolving definitions, the current preventive strategies and the management of this problem.

关键词： Pancreatic fistula Pancreaticoduodenectomy Pancreatic anastomosis Pancreatic anastomotic failure Complications

Stability Analysis of Network Controlled Temperature Control System with Additive delays

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Computer Modeling in Engineering & Sciences 2018年第3期114卷 321-334页

作者： v.venkatachalam d.Prabhakaran department of Chemical Engineering Coimbatore Institute of TechnologyCoimbatore-641014India

This paper presents,using Lyapunov-Krasovskii functional technique combined with reciprocal convex lemma is considered for a networked control temperature control system with additive *** the stability analysis,a new LK functional is assumed,and take the time-derivative of the(LK)functional,using reciprocal convex combination technique was employed to obtain less conservative stability ***,the proposed stability analysis culminates into a stability criterion in the LMI(linear matrix inequalities)*** results obtained are in accordance with the theoretically obtained in the temperature control system and they are closer to the standard benchmark temperature-control system.

关键词： delay-dependent stability time-varying additive delays temperature control heat exchanger lyapunov-krasovskii functional linear matrix inequality reciprocal convex lemma

SCIENTIFIC PRINCIPLES FOR MOdIFICATION OF WATER-SOLUBLE POLYMERS. FORMATION OF MACROMOLECULAR COMPLEXES

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Chinese Journal of Polymer Science 1998年第3期16卷 268-278页

作者： PAUTOv v.d. ANUFRIEvA E.v. KRAKOvYAK M.G. Institute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 Russia

The study of nanosecond dynamics of macromolecules with the lumines-cent methods make it possible to investigate the formation and functioning of polymericcomplexes, polymeric conjugates and macromolecular metal complexes, which are widelyused for solving many practical tasks. The nanosecond dynamics of macromolecules are ahighly sensitive indicator of interpolymer complexes (IPC) formation. It enables us to solvethe problems of studying IPC formation and stability and to investigate the interpolymerreactions of exchange and substitution. The investigation of changes in the rotational mo-bility of globular protein molecules as a whole makes it possible to determine the complexcomposition and its stability, and to control the course of polymer-protein conjugate forma-tion reaction. The nanosecond dynamics of polymers interacting with surfacants' ions (S)are the sensitive indicator of the S-polymer complex formation. A method for determin-ing the equilibrium constants of the S-polymer complex formation was developed on thebasis of the study of polymer chains mobility. It is established that nanosecond dynamicsinfluences the course of chemical reactions in polymer chains. Moreover, the marked effectof the nanosecond dynamics is also revealed in the study of photophysical processes (theformation of excimers and energy migration of electron excitation) in polymers with pho-toactive groups. It was found that the efficiency of both processes increases with increasingthe mobility of side chains, the carriers of photoactive groups.

关键词： Modification of water-soluble polymers Formation of complexes

Stability Analysis of Cyber-Physical Micro Grid Load Frequency Control System with Time-varying delay and Non-Linear Load Perturbations

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Computer Modeling in Engineering & Sciences 2019年第12期121卷 801-813页

作者： d.vijeswaran v.Manikandan department of Electrical and Electronics Engineering Coimbatore Institute of TechnologyCoimbatore 641014India 不详

In a cyber-physical micro-grid system,wherein the control functions are executed through open communication channel,stability is an important issue owing to the factors related to the time-delay encountered in the data *** of feedback variable as discrete data packets in communication network invariably introduces inevitable time-delays in closed loop control *** delay,depending upon the network traffic condition,inherits a time-varying characteristic;nevertheless,it adversely impacts the system performance and *** load perturbations in a micro-grid system are considerably influenced by the presence of fluctuating power generators like wind and solar *** these non-conventional energy sources are integrated into the power grid through power electronic interface circuits that usually works at high switching frequency,noise signals are introduced into the micro-grid system and these signals gets super-imposed to the load *** on this back ground,in this paper,the delay-dependent stability issue of networked micro-grid system combined with time-varying feedback loop delay and uncertain load perturbations is investigated,and a deeper insight has been presented to infer the impact of time-delay on the variations in the system *** classical Lyapunov-Krasovskii method is employed to address the problem,and using a standard benchmark micro-grid system,and the proposed stability criterion is validated.

关键词： delay-dependent stability time-varying delay open communication network nonlinear perturbations Lyapunov-Krasovskii functional linear Matrix Inequality(LMI)

Relativistic Landau quantization in the spiral dislocation spacetime

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Communications in Theoretical Physics 2021年第2期73卷 68-72页

作者： A v d M Maia K Bakke departamento de Fisica Universijade Federal da ParaibaCaixa Postal 500858051-900Joao PessoaPBBrazil

We analyse the interaction of a relativistic electron with a uniform magnetic field in the spiral dislocation *** show that analytical solutions to the dirac equation can be obtained,where the spectrum of energy corresponds to the relativistic Landau *** also analyse the influence of the spiral dislocation on the relativistic Landau levels by showing that there exists an analogue of the Aharonov–Bohm effect for bound states.

关键词： spiral dislocation spacetime relativistic Landau quantization Aharonov-Bohm effect relativistic wave equations dirac equation

Coarsening rate of microstructure in semi-solid aluminium alloys

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1672-1676页

作者： H.v.ATKINSON d.LIU Mechanics of Materials Research Group Department of EngineeringUniversity of LeicesterUniversity Rd. Now with Wolfson Microelectronics PLC.

The rate of microstructural coarsening of recrystallisation and partial melting (RAP) and cooling slope (CS) processed materials in the semi-solid state is compared with rates found in the *** rate of coarsening depended on the liquid fraction but RAP route 2014 alloy with 37% liquid coarsened slightly more slowly than the CS route 2014 alloy with a lower liquid fraction of 17%, contrary to *** the CS route, an increase in liquid fraction resulted in faster coarsening.A modified 2014 alloy with Fe, Mn and Zn stripped out of the composition gave a relatively high coarsening *** coarsening rate was also relatively high for CS 201 alloy in comparison with either RAP 2014 or CS *** coarsening rates are thought to be associated with the presence of particles which inhibit the migration of liquid film grain *** could be the result of pinning or of the liquid film impeding diffusion at the boundary.

关键词： coarsening semi-solid metal 2014 alloy recrystallisation and partial melting cooling slope

Interacting tachyonic scalar field

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Communications in Theoretical Physics 2021年第2期73卷 102-107页

作者： A Kundu S d Pathak v K Ojha department of Physies Lovely Professional UniversityPhagwaraPunjab144411India School of Sciences SAGE University BhopalMadhya Pradesh462022India

We discuss the coupling between dark energy and matter by considering a homogeneous tachyonic scalar field as a candidate for dark *** obtained the functional form of scale factor by assuming that the coupling strength depends linearly on the Hubble parameter and energy *** also estimated the cosmic age of the Universe for different values of coupling constant.

关键词： dark energy dark matter scalar field achyonic scalar field

Optical theorem,crossing property,and derivative dispersion relations:implications on the asymptotic behavior of σ_(tot)(s) and ρ(s)

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Chinese Physics C 2022年第8期46卷 72-90页

作者： S.d.Campos v.A.Okorokov Applied Mathematics Laboratory-CCTS/dFQM Federal University of São CarlosSorocaba CEP 18052-780Brazil Moscow Engineering Physics Institute National Research Nuclear University MEPhI115409 MoscowRussia

In this paper,we present some results on the behavior of the total cross section and p-parameter at asymptotic energies in proton-proton(pp) and antiproton-proton(pp) ***,we consider three of the main theoretical results in high energy physics:the crossing property,derivative dispersion relation,and optical *** use of such machinery facilitates the derivation of analytic formulas for a wide set of the measured global scattering parameters and some important relations between *** suggested parameterizations approximate the energy dependence for the total cross section and ρ-parameter for pp and pp with a statistically acceptable quality in the multi-Tev ***,the qualitative description is obtained for important interrelations,namely difference,sum,and ratio of the antiparticle-particle and particle-particle total cross *** the reduced number of experimental data for the total cross section and p-parameter at the Tev-scale,which complicates any prediction for the beginning of the asymptotic domain,the fitting procedures indicates that asymptotia occur in the energy range 25.5-130 ***,in the asymptotic regime,we obtain α_(P)=1.A detailed quantitative study of the energy behavior of the measured scattering parameters and their combinations in the ultra-high energy domain indicates that the scenario with the generalized formulation of the Pomeranchuk theorem is more favorable with respect to the original formulation of this theorem.

关键词： optical theorem derivative dispersion relations asymptotic behavior Pomeranchuk theorem