检索结果-南通市图书馆

From conventional two-stage hepatectomy to ALPPS:Fifteen years of experience in a hepatobiliary surgery unit

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2021年第6期20卷 542-550页

作者： Javier Maupoey Ibáñez Eva María MontalváOrón Andrea BoscàRobledo Alonso Camacho Ramírez Ana Hernando Sanz Pablo Granero castro Alberto Alegre Delgado rafael López-Andújar Hepatobiliary Surgery and Transplant Unit La Fe University and Polytechnic HospitalValenciaSpain Department of Radiology La Fe University and Polytechnic HospitalValenciaSpain

Background:Hepatectomy in patients with large tumor load may result in postoperative liver failure and associated complications due to excessive liver parenchyma *** two-stage hepatectomy(TSH)and associating liver partition and portal vein ligation for staged hepatectomy(ALPPS)technique are possible solutions to this *** liver metastases(CRLM)is the most frequent indication,and there is a need to assess outcomes for both techniques to improve surgical and long-term oncological outcomes in these ***:A single-center retrospective study was designed to compare TSH with ALPPS in patients with initially unresectable bilateral liver tumors between January 2005 and January *** was performed from January 2012 onwards as the technique of ***-term overall survival(OS)and disease-free survival(DFS)were evaluated as primary outcome in CRLM *** morbidity,mortality and liver growth in all patients were also ***:A total of 38 staged hepatectomies were performed:17 TSH and 21 *** resection rate was 76.5%(n=13)in the TSH group and 85.7%(n=18)in the ALPPS group(P=0.426).Overall major morbidity(Clavien-Dindo≥3 a)(stage 1+stage 2)was 41.2%(n=7)in TSH and 33.3%(n=7)in ALPPS patients(P=0.389),and perioperative 90-day mortalities were 11.8%(n=2)vs.19.0%(n=4)in each group,respectively(P=0.654).Intention-to-treat OS rates at 1 and 5 years in CRLM patients for TSH(n=15)were 80%and 33%,and for ALPPS(n=17)76%and 35%,*** rates at 1 and 5 years were 36%and 27%in the TSH group vs.33%and 27%in the ALPPS group,***:ALPPS is an effective alternative to TSH in bilateral affecting liver tumors,allowing higher resection rate,but patients must be carefully *** CRLM patients similar long-term OS and DFS can be achieved with both techniques.

关键词： ALPPS Two-stage hepatectomy Colorectal liver metastases Posthepatectomy liver failure

Modeling and simulation of circulating fluidized bed reactors applied to a carbonation/calcination loop

在线全文

学校读者我要写书评

暂无评论

Particuology 2014年第4期12卷 116-128页

作者： rafael A.Sánchez Hugo A.Jakobsen Department of Chemical Engineering Norwegian University of Science and Technology7034 TrondheimNorway

A fluid dynamic model for a gas-solid circulating fluidized bed （CFB） designed using two coupled riser reactors is developed and implemented numerically with code programmed in Matlab. The fluid dynamic model contains heat and species mass balances to calculate temperatures and compositions for a carbonation/calcination loop process. Because of the high computational costs required to resolve the three-dimensional phenomena, a model representing a trade-offbetween computational time requirements and accuracy is developed. For dynamic processes with a solid flux between the two reactor units that depends on the fluid dynamics of both risers, a dynamic one-dimensional two-fluid model is sufficient. A two-fluid model using the constant particle viscosity closure for the stress term is used for the solid phase, and an algebraic turbulence model is applied to the gas phase. The numerical model implementa- tion is based on the finite volume method with a staggered grid scheme. The exchange of solids between the reactor units constituting the circulating fluidized bed （solid flux） is implemented through additional mass source/sink terms in the continuity equations of the two phases, For model validation, a relevant experimental analysis provided in the literature is reproduced by the numerical simulations, The numerical analysis indicates that sufficient heat integration between the two reactor units is important for the performance of the circulating fluidized bed system, The two-fluid model performs fairly well for this chemical process operated in a CFB designed as two coupled riser reactors. Further analysis and optimization of the solution algorithms and the reactor coupling strategy is warranted.

关键词： Chemical reactors Fluidization Mathematical modeling Multiphase flow Simulation

A Simple and Efficient Structural Topology Optimization Implementation Using Open-Source Software for All Steps of the Algorithm:Modeling, Sensitivity Analysis and Optimization

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2023年第8期136卷 1371-1397页

作者： rafael Marin Ferro Renato Pavanello Coordination of Mechanical Engineering Federal Institute of Science and Technology of ES-IFESAracruz-ES29192-733Brazil Department of Computational Mechanics Faculty of Mechanical EngineeringUnicampCampinas-SP13083-860Brazil

This work analyzes the implementation of a continuous method of structural topology optimization(STO)using open-source software for all stages of the topology optimization problem:modeling,sensitivity analysis and *** implementation involves three main components:numerical analysis using the Finite Element Method(FEM),sensitivity analysis using an Adjoint method and an optimization *** order to allow the automated numerical solution of Partial Differential Equations(PDEs)and perform a sensitivity analysis,FEniCS and Dolfin Adjoint software are used as tools,which are open-source *** the optimization process,Ipopt(Interior Point OPTimizer)is used,which is a software package for nonlinear optimization scale designed to find(local)solutions of mathematical optimization *** topological optimization method used is based on the SIMP-Solid IsotropicMaterial with Penalization *** considered problem is the minimization of compliance/maximization of stiffness,considering the examples of recurrent structures in the literature in 2D and 3D.A density filtering algorithm based on Helmholtz formulation is *** complete code involves 51 lines of programming and is presented and commented in detail in this article.

关键词： Structural topology optimization finite element method FEniCS Dolfin Adjoint

TWO NOVEL GRADIENT METHODS WITH OPTIMAL STEP SIZES

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2021年第3期39卷 375-391页

作者： Harry Oviedo Oscar Dalmau rafael Herrera Centro de Investigacion en Matematicas CIMAT A.C.GuanajuatoGto.Mexico

In this work we introduce two new Barzilai and Borwein-like steps sizes for the classical gradient method for strictly convex quadratic optimization *** proposed step sizes employ second-order information in order to obtain faster gradient-type *** step sizes are derived from two unconstrained optimization models that involve approximate information of the Hessian of the objective function.A convergence analysis of the proposed algorithm is *** numerical experiments are performed in order to compare the efficiency and effectiveness of the proposed methods with similar methods in the ***,it is observed that our proposals accelerate the gradient method at nearly no extra computational cost,which makes our proposal a good alternative to solve large-scale problems.

关键词： Gradient methods Convex quadratic optimization Hessian spectral properties Steplength selection

Heterogeneous catalysis under flow for the 21st century fine chemical industry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2021年第2期6卷 161-166页

作者： Rosaria Ciriminna Mario Pagliaro rafael Luque Istituto per Io Studio dei Mate riali Nanostnuturati CNRwia U.La Malfa 15390146PulemoItaly Deparamento de Quimica Orginica Univeridad de CordobaCampus de RabonalesEdificio Marie Curie(C-3)Cra Nnal IV-Akm 396Cordoba14014Spain Peoples Friendship University of Russia(RUDN Universiy) 6 Miklukho Maklaya St117198MoscowRussia

Due to metal leaching and poor catalyst stability, the chemical industry's fine chemical and pharmaceutical sectors have been historically reluctant to use supported transition metal catalysts to manufacture fine chemicals and active pharmaceutical ingredients. With the advent of new generation supported metal catalysts and flow chemistry, we argue in this study, this situation is poised to quickly change. Alongside heterogenized metal nanoparticles, both single-site molecular and single-atom catalyst will become ubiquitous. This study offers a critical outlook taking into account both technical and economic aspects.

关键词： Fine chemical Heterogeneous catalysis Single atom catalysis Green chemistry Chemical industry

PD-L1 expression associated with better response to EGFR tyrosine kinase inhibitors

在线全文

学校读者我要写书评

暂无评论

Cancer Biology & Medicine 2015年第2期12卷 71-73页

作者： rafael Rosell Ramón Palmero Molecular Oncology Research (MORe) Foundation Catalan Institute of Oncology Hospital Germans Trias i Pujol Germans Trias i Pujol Health Sciences Institute and Hospital Campus Can Ruti Instituto Oncológico Dr Rosell Quiron Dexeus University Hospital Pangaea Biotech Thoracic Oncology Unit Department of Medical Oncology Catalan Institute of Oncology L'Hospitalet

Cancer evades host immune surveillance by using immune checkpoints,w hich are inhibitor y pathways cr ucial for maintaining *** cells express multiple inhibitory ligands,and tumor-infiltrating lymphocytes(TIL)express ... 详细信息

关键词：酪氨酸激酶抑制剂 EGFR 细胞毒性T淋巴细胞宿主免疫肿瘤浸润 CTLA-4 程序性死亡抑制途径

On formalism and stability of switched systems

在线全文

学校读者我要写书评

暂无评论

Control Theory and Technology 2012年第2期10卷 176-183页

作者： John LETH rafael WISNIEWSKI Department of Electronic Systems Automation and ControlAalborg UniversityFredrik Bajers Vej 7 C9220 Aalborg EastDenmark

In this paper, we formulate a uniform mathematical framework for studying switched systems with piecewise linear partitioned state space and state dependent switching. Based on known results from the theory of differential inclusions, we devise a Lyapunov stability theorem suitable for this class of switched systems. With this, we prove a Lyapunov stability theorem for piecewise linear switched systems by means of a concrete class of Lyapunov functions. Contrary to existing results on the subject, the stability theorems in this paper include Filippov (or relaxed) solutions and allow infinite switching in finite time. Finally, we show that for a class of piecewise linear switched systems, the inertia of the system is not sufficient to determine its stability. A number of examples are provided to illustrate the concepts discussed in this paper.

关键词： Switched systems Differential inclusions Stability Inertia Quadratic forms

Altered histone retention and epigenetic modifications in the sperm of infertile men

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2012年第2期14卷 239-240页

作者： rafael Oliva Josep Luis Ballesca Genetics Unit Department of Physiological Sciences I University of Barcelona Biochemistry and Molecular Genetics Service and Andrology Unit Hospital Clinic 08036 Barcelona Spain

It is well know that the nuclei of spermatogenic cells experience one of the most extremely marked chromatin changes known in cells. At the end of spermatogenesis, the histones are removed in many species and the DNA ... 详细信息

关键词： sperm Genetics Altered histone

Performance evaluation of lateral canopy shakers with catch frame for continuous harvesting of oranges for juice industry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2020年第3期13卷 88-93,F0002页

作者： rafael R.Sola-Guirado Sergio castro-Garcia Gregorio L.Blanco-Roldán Jesús A.Gil-Ribes Emilio J.González-Sánchez Universidad de Córdoba Departamento de Ingeniería RuralE.T.S.I.Agronómica y de MontesCampus de RabanalesCtra.Nacional IV Km 396CordobaSpain

Citrus is mainly oriented to fresh consumption,and harvesting is usually performed ***,the high cost of harvesting and the low availability of labour can compromise the profitability of the crop when it is destined to juice *** development of citrus mechanical harvesting for industrial processing is conditioned to reach a high fruit removal efficiency,with a reduced damage to both fruit and *** current machines available are very large,requiring extensive plantations with long rows of trees to be *** this study,two lateral canopy shakers equipped with a catch frame were evaluated to harvest independently both sides of the hedge on intensive citrus plantations with the main objective of determining their performance and *** lateral canopy shakers tested were three tractor-drawn machines,one commercial machine and two *** tested machines reached a mean value of 78%of fruit ***,the prototypes,equipped with a catch frame,were able to recover a mean value of 70%of *** the results were promising,for achieving an efficient result,the application of this harvesting technology still requires a process of improvement,and the adaptation of both the machine and the *** machines should reduce the amount of post-harvest ground fruit(5.9%-10.4%).Tree damages generated by the contact of the catch frame with the trunk and the metal rods with main branches were the most ***,it is still necessary to increase the ground speed of the machinery and improving the design of the rods,regulating the rod penetrating deep in the canopy to improve the fruit recovery and limit the damage caused to the trees.

关键词： harvester mechanical harvesting fruit removal tree damage Citrus sinensis L.Osbeck