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On formalism and stability of switched systems

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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

Timing of surgery in Crohn’s disease: A key issue in the management

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World Journal of Gastroenterology 2008年第36期14卷 5532-5539页

作者： rafael Alós Joaquín Hinojosa Servicio de Cirugía General Unidad de Coloproctología Hospital de Sagunto Valencia Spain Unidad de Digestivo Servicio de Medicina Interna Hospital de Sagunto Valencia Spain

The timing of the decision for operation in Crohn’s disease is based on an evaluation of the several factors such as the failure of medical treatment, complications due to the Crohn’s disease or to the farmacological therapy, development of dysplasia or cancer and growth retardation. A complete evaluation of these factors should result in operation timed to the patient’s best advantage, achieving maximal relief of symptoms with improvement of quality of life. Given the complexity and heterogeneity of the disease and the different options for treatment, is difficult to systematize when the optimal moment for the surgery is arrived. A very important factor in the management of Crohn’s disease is the multidisciplinary approach and the patient preference should be a significant factor in determining the choice of therapy. The surgery should be considered such another option in the sequential treatment of Crohn’s disease. We have analyzed the factors that are involved in the decision taking of the surgical treatment regarding to the experience and the published literature. When did the medical therapy fail? when is the appropriate moment to operate on the patient? Or which complications of Crohn’s disease need a surgery? These are some of the questions we will try to answer.

关键词： Crohn's disease Surgical treatment Medical therapy

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

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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： Sustainability Environmental sciences Biogeography Biogeochemistry

Analysing the quality of Swiss National Forest Inventory measurements of woody species richness

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Forest Ecosystems 2020年第3期7卷 478-488页

作者： Berthold Traub rafael O.Wüest Scientific Service NFI Swiss Federal Research Institute WSLZürcherstrasse 1118903BirmensdorfSwitzerland Spatial Evolutionary Ecology Swiss Federal Research Institute WSLZürcherstrasse 1118903BirmensdorfSwitzerland

Background: Under ongoing climate and land-use change, biodiversity is continuously decreasing and monitoring biodiversity is becoming increasingly important. National Forest Inventory(NFI) programmes provide valuable timeseries data on biodiversity and thus contribute to assessments of the state and trends in biodiversity, as well as ecosystem functioning. Data quality in this context is of paramount relevance, particularly for ensuring a meaningful interpretation of changes. The Swiss NFI revisits about 8%–10% of its sample plots regularly in repeat surveys to supervise the quality of ***: We analysed the relevance of observer bias with equivalence tests, examined data quality objectives defined by the Swiss NFI instructors, and calculated the pseudo-turnover(PT) of species composition, that is, the percentage of species not observed by both teams. Three attributes of woody species richness from the latest Swiss NFI cycles(3 and 4) were analysed: occurrence of small tree and shrub species(1) on the sample plot and(2) at the forest edge, and(3) main shrub and trees species in the upper ***: We found equivalent results between regular and repeat surveys for all attributes. Data quality, however,was significantly below expectations in all cases, that is, as much as 20%–30% below the expected data quality limit of 70%–80%(proportion of observations that should not deviate from a predefined threshold). PT values were about 10%–20%, and the PT of two out of three attributes decreased significantly in NFI4. This type of uncertainty –typically caused by a mixture of overlooking and misidentifying species – should be considered carefully when interpreting change figures on species richness estimates from NFI ***: Our results provide important information on the data quality achieved in Swiss NFIs in terms of the reproducibility of the collected data. The three applied approaches proved to be effective for evaluating the quality of plot

关键词： Biodiversity Data quality Equivalence test Forest inventory Monitoring Observer agreement Richness Pseudo-turnover

Immersed Boundary Approach to Biofilm Spread on Surfaces

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Communications in Computational Physics 2022年第1期31卷 257-292页

作者： Ana Carpio rafael Gonzalez-Albaladejo Departamento de Matematica Aplicada Universidad Complutense28040 MadridSpain

We propose a computational model to study the growth and spread of bacterial biofilms on interfaces,as well as the action of antibiotics on *** membranes are represented by boundaries immersed in a fluid matrix and subject to interaction ***,division and death of bacterial cells follow dynamic energy budget rules,in response to variations in environmental concentrations of nutrients,toxicants and substances released by the *** this way,we create,destroy and enlarge boundaries,either spherical or *** forces represent details of the interaction between cells,and the interaction with the *** can investigate geometrical arrangements and the formation of porous *** simulations illustrate the evolution of top views and diametral slices of small biofilm seeds,as well as the action of *** show that cocktails of antibiotics targeting active and dormant cells can entirely eradicate a biofilm.

关键词： Hybrid multiscale models immersed boundary methods dynamic energy budget models bacterial biofilm antibiotic resistance

A closer look at cannabimimetic terpenes, polyphenols, and flavonoids: a promising road forward

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Neural Regeneration Research 2021年第7期16卷 1433-1435页

作者： Juliana Cavalli rafael Cypriano Dutra Laboratory of Autoimmunity and Immunopharmacology Department of Health SciencesCenter of AraranguáFederal University of Santa CatarinaAraranguáSCBrazil Post-Graduate Program of Neuroscience Center of Biological SciencesFederal University of Santa CatarinaFlorianópolisSCBrazil

Despite the current interest in the potential medical use of Cannabis, it is worth remembering that cannabis is not a new drug, with both a nonmedical and medical history supporting its *** history advanced in scientific strength and importance worldwide when Professor Raphael Mechoulam and colleagues initiated their pioneering discoveries in *** first, Mechoulam et al.(1972) achieved the complete synthesis of the pure compounds from hashish(including △1-tetrahydrocannabinol and other neutral cannabinoids such as cannabigerol, cannabichromene, and cannabicyclol), and established their molecular structures.

关键词： closer initiated neutral

Involvement of substance P and the NK-1 receptor in pancreatic cancer

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World Journal of Gastroenterology 2014年第9期20卷 2321-2334页

作者： Miguel Muoz rafael Coveas Virgen del Rocío University Hospital Research Laboratory on Neuropeptides (IBIS) 41013 Seville Spain Institute of Neurosciences of Castilla y León (INCYL) Laboratory of Neuroanatomy of the Peptidergic Systems (Lab 14) University of Salamanca 37007 Salamanca Spain

Pancreatic cancer is the fourth leading cause of cancer related-death for both men and women and the 1-and5-year relative survival rates are 25%and 6%,***,it is urgent to investigate new antitumor drugs to improve the survival of pancreatic cancer *** peptide substance P(SP)has a widespread distribution throughout the *** binding to the neurokinin-1(NK-1)receptor,SP regulates biological functions related to cancer,such as tumor cell proliferation,neoangiogenesis,the migration of tumor cells for invasion,infiltration and metastasis,and it exerts an antiapoptotic effects on tumor *** is known that the SP/NK-1 receptor system is involved in pancreatic cancer progression:(1)pancreatic cancer cells and samples express NK-1 receptors;(2)the NK-1 receptor is overexpressed in pancreatic cancer cells in comparison with non-tumor cells;(3)nanomolar concentrations of SP induce pancreatic cancer cell proliferation;(4)NK-1 receptor antagonists inhibit pancreatic cell proliferation in a concentration-dependent manner,at a certain concentration,these antagonists inhibit100%of tumor cells;(5)this antitumor action is medi-ated through the NK-1 receptor,and tumor cells die by apoptosis;and(6)NK-1 receptor antagonists inhibit angiogenesis in pancreatic cancer *** these data suggest that the SP/NK-1 receptor system could play an important role in the development of pancreatic cancer;that the NK-1 receptor could be a new promising therapeutic target in pancreatic cancer,and that NK-1 receptor antagonists could improve the treatment of pancreatic cancer.

关键词： Pancreas Substance P Neurokinin-1 receptor antagonists Apoptosis Antitumor Angiogenesis Metastasis Pancreatic cancer

Quercetin prevents spinal motor neuron degeneration induced by chronic excitotoxic stimulus by a sirtuin 1-dependent mechanism

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Translational Neurodegeneration 2017年第1期6卷 310-323页

作者： rafael Lazo-Gomez Ricardo Tapia División de Neurociencias Instituto de Fisiología CelularUniversidad Nacional Autónoma de MéxicoCircuito exterior s/nCiudad UniversitariaCoyoacán04510 Ciudad de MéxicoMexico

Background:Excitotoxicity is a mechanism of foremost importance in the selective motor neuron degeneration characteristic of motor neuron *** therapeutic strategies are an unmet need for these ***,such as quercetin and resveratrol,are plant-derived compounds that activate sirtuins(SIRTs)and have shown promising results in some models of neuronal death,although their effects have been scarcely tested in models of motor neuron ***:In this work we investigated the effects of quercetin and resveratrol in an in vivo model of excitotoxic motor neuron death induced by the chronic infusion ofα-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid(AMPA)into the rat spinal cord *** and resveratrol were co-infused with AMPA and motor behavior and muscle strength were assessed daily for up to ten ***,animals were fixed and lumbar spinal cord tissue was analyzed by histological and immunocytological ***:We found that the chronic infusion of AMPA[1 mM]caused a progressive motor neuron degeneration,accompanied by astrogliosis and microgliosis,and motor deficits and paralysis of the rear *** infusion ameliorated AMPA-induced paralysis,rescued motor neurons,and prevented both astrogliosis and microgliosis,and these protective effects were prevented by EX527,a very selective SIRT1 *** contrast,neither resveratrol nor EX527 alone improved motor behavior deficits or reduced motor neuron degeneration,albeit both reduced ***:These results suggest that quercetin exerts its beneficial effects through a SIRT1-mediated mechanism,and thus SIRT1 plays an important role in excitotoxic neurodegeneration and therefore its pharmacological modulation might provide opportunities for therapy in motor neuron disorders.

关键词： Motor neuron disorder Quercetin Resveratrol Sirtuin Excitotoxicity

Clinical Misdiagnosis of Steatocystoma Simplex of Eyebrow in a Pediatric Patient

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Chinese Medical Journal 2016年第3期129卷 377-378页

作者： Karin Milleni Araujo rafael Denadai Department of Internal Medicine Hospital Municipal Walter Ferrari Campinas Sao Paulo Brazil Institute of Plastic and Craniofacial Surgery SOBRAPAR Hospital Campinas Sao Paulo Brazil

To the Editor： A 4-year-old girl presented with a 16-month history of swelling of the *** and general surgeons diagnosed her with sebaceous cyst, and because of unsuccessful treatment with two surgical drainages and antibiotic therapy, she was referred to our *** examination, a soft, freely movable, nontender subcutaneous lesion was noted on the lefteyebrow [Figure 1].

关键词： history eyebrow surgeons