检索结果-南通市图书馆

Chinese Journal of Chemistry 2017年第12期35卷 1881-1888页

作者： Fernando Ortega-Jiménez josé guillermo penieres-carrillo josé Guadalupe López-Cortés M. Carmen Ortega-Alfaro Selene Lagunas-Rivera Departamento de Cieneias Qulmicas Facultad de Estudios Superiores Cuautitlān-UNAM Campo i Avenida lro. de Mayo s/n Cuautitlán Izcalli C.P. 54740 Estado de México México Instituto de Qulmiea UNAM Circuito Exterior Ciudad Universitaria Coyoacán C.P. 04360 Cuidad de México México Instituto de Ciencias Nucleares UNAM Circuito Exterior Ciudad Universitaria Coyoacán C.P. 04360 Ciudad de México México Catedrático CONA CyT-TecNM-Instituto Tecnológico de Tuxtla Gutiérrez Carretera Panamericana Km 1080 Col Juan Crispin Tuxtla Gutiérrez C.P. 29050 Chiapas México

A simple arylhydrazone containing the benzothiazole moiety which may be used as an efficient ligand in the palladium-catalyzed Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions, under infrared irradiation as an alternative source of energy, is presented. The reactions proceeded with extremely high efficiency under mild conditions and produced very good yields.

关键词： arylhydrazones palladium-catalyzed cross-coupling reaction IR-irradiation

A PD-Type State-Dependent Riccati Equation With Iterative Learning Augmentation for Mechanical Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第8期9卷 1499-1511页

作者： Saeed Rafee Nekoo joséÁngel Acosta guillermo Heredia Anibal Ollero GRVC Robotics Lab. Depto de Ingeniería de Sistemas y AutomáticaEscuela Técnica Superior de IngenieríaUniversidad de SevillaSeville 41092Spain

This work proposes a novel proportional-derivative(PD)-type state-dependent Riccati equation(SDRE)approach with iterative learning control(ILC)*** the one hand,the PD-type control gains could adopt many useful available criteria and tools of conventional PD *** the other hand,the SDRE adds nonlinear and optimality characteristics to the controller,i.e.,increasing the stability *** advantages with the ILC correction part deliver a precise control law with the capability of error reduction by *** SDRE provides a symmetric-positive-definite distributed nonlinear suboptimal gain K(x)for the control input law u=–R–1(x)BT(x)K(x)*** sub-blocks of the overall gain R–1(x)BT(x)K(x),are not necessarily symmetric positive definite.A new design is proposed to transform the optimal gain into two symmetric-positive-definite gains like PD-type controllers as u=–KSP(x)e–KSD(x)?.The new form allows us to analytically prove the stability of the proposed learning-based controller for mechanical systems;and presents guaranteed uniform boundedness in finite-time between learning *** symmetric PD-type controller is also developed for the state-dependent differential Riccati equation(SDDRE)to manipulate the final *** SDDRE expresses a differential equation with a final boundary condition,which imposes a constraint on time that could be used for finitetime ***,the availability of PD-type finite-time control is an asset for enhancing the conventional classical linear controllers with this *** learning rules benefit from the gradient descent method for both regulation and tracking *** of the advantages of this approach is a guaranteed-stability even from the first loop of learning.A mechanical manipulator,as an illustrative example,was simulated for both regulation and tracking *** experimental validation was done to show the capability of the system in practice by the implementation of the proposed metho

关键词： Closed-loop iterative learning control(ILC) PD-type SDRE SDDRE symmetric

Influence of steel jacket thickness on the RC bridges' seismic vulnerability

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2019年第1期6卷 15-34页

作者： Bertha Olmos josé Manuel Jara Gerardo Gómez guillermo Martínez Department of Civil Engineering Universidad Michoacana de San Nicolas de Hidalgo

The seismic demands of bridges subjected to strong earthquakes are mostly concentrated on piers. The main objective of this study is to assess the seismic vulnerability of retrofitted bridges with steel jackets. It analyzes the influence of the steel jacket thickness on the seismic capacity and demand of bridges. The bridges in study have two simple supported spans with superstructure composed by AASHTO type girders and a substructure formed with one circular pier over a stiff foundation. They are located on the Pacific coast of Mexico that is a zone of high seismicity. The bridges seismic capacity are evaluated through nonlinear static analyses and the shear force and displacement demands were determined using capacity spectra with a group of 10 real accelerograms from a subduction source. The response spectra were scaled to several peak ground accelerations(PGA) with the aim to estimate four damage scenarios linked each one to a probability of exceedance in a specific period, for return periods in the range of 72-3500 years that represent service level and maximum considered earthquake. Results show that the confining effect provided by the steel jackets substantially improves the seismic performance of the bridges piers. The increase of jacket thickness guides to important increments on columns base shear capacity, and the influence of the steel jacket thickness depends on the limit state and bridge slenderness ratio.

关键词： Steel jacket Piers’retrofit Subduction earthquakes RC piers’vulnerability

Hemoconcentration is a poor predictor of severity in acute pancreatitis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第44期11卷 7018-7023页

作者： josé M.Remes-Troche Andrés Duarte-Rojo Gustavo Morales guillermo Robles-Díaz Department of Gastroenterology

AIM： To determine whether the hematocrit （Hct） at admission or at 24 h after admission was associated with severe acute pancreatitis （AP）, organ failure （OF）, and pancreatic necrosis. METHODS： A total of 336 consecutive patients with a first AP episode were studied. Etiology, Hct values at admission and at 24 h, development of severe AP according to Atlanta＇s criteria, pancreatic necrosis, OF and mortality were recorded. Hemoconcentration was defined as Hct level 〉44% for males and 〉40% for females. The t-test and ;x^2 test were used to assess the association of hemoconcentration to the severity, necrosis and OF. Diagnostic accuracy was also determined. RESULTS： Biliary disease was the most frequent etiology （n = 148）. Mean Hct levels at admission were 41±6% for females and 46±7% for males （P〈0.01）. Seventyeight （23%） patients had severe AP, and OF developed in 45 （13%） patients. According to contrast-enhanced computed tomography scan, 36% （54/150） patients showed pancreatic necrosis. Hct levels were elevated in 58% （55/96） and 61% （33/54） patients with interstitial and necrotizing pancreatitis, respectively. Neither Hct levels at admission nor hemoconcentration at 24 h were associated with the severity, necrosis or OF. Sensitivity, specificity and positive predictive values for both determinations were very low; and negative predictive values were between 61% and 86%, being the highest value for OF. CONCLUSION： Hct is not a useful marker to predict a worse outcome in acute pancreatitis. In spite of the high negative predictive value of hemoconcentration, the prognosis gain is limited due to an already high incidence of mild disease.

关键词： Acute pancreatitis Hernatocrit Hemoconcentration Severity Necrosis

Physiological dormancy broken by endozoochory:Austral parakeets(Enicognathus ferrugineus)as legitimate dispersers of calafate(Berberis microphylla)in the Patagonian Andes

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 Plant Ecology 2020年第5期13卷 538-544页

作者： Carolina Bravo Daniel Chamorro Fernando Hiraldo Karina Speziale Sergio A.Lambertucci joséL.Tella guillermo Blanco Department of Evolutionary Ecology Museo Nacional de Ciencias NaturalesCSICJoséGutiérrez Abascal 228006 MadridSpain Centre d’Etudes Biologiques de Chizé UMR 7372CNRS and La Rochelle UniversitéF-79360 Beauvoir-sur-NiortFrance Departamento de Ciencias Ambientales Universidad de Castilla-La ManchaAv.Carlos III s/n45071 ToledoSpain Department of Conservation Biology Estación Biológica de DoñanaCSICAmérico Vespucio 2641092 SevillaSpain Grupo de Investigaciones en Biología de la Conservación Departamento de EcologíaINIBIOMA(CONICET-National University of Comahue)Pasaje Gutiérrez 11258400 BarilocheArgentina

Aims Seed dispersal by endozoochory is an important process in plant regeneration and the establishment of new *** with dormancy may especially benefit after disperser gut ***,the ways in which gut passage affect the germination of plant species with physiological dormancy remain ***,we experimentally assessed the mutualistic interaction between the Austral parakeet(Enicognathus ferrugineus)as a disperser of calafate(Berberis microphylla),a thorny bush inhabiting the understory of the Austral temperate forests of South America with seeds that are characterized by deep physiological *** Germination success and viability of calafate seeds obtained from faeces and from intact fruits were tested under four treatments:(i)digested seeds,(ii)digested seeds with faecal extract,(iii)intact seeds from fruit and(iv)intact seeds from fruit with *** Findings About 65%of the Austral parakeet droppings contained calafate *** of seeds did not differ between ***,germination was significantly higher in digested seeds than in intact seeds from fruits,while no difference was found between faecal and pulp *** faecal matter nor fruit pulp provided seeds with any ecological advantages derived from enhancing germinability,but did confer some disadvantage in germination *** matter is expected to be completely lacking around seeds after several months under snow before germinating in the following spring,given intense washing due to persistent rain and the spring thaw in the Patagonian *** higher germinability along with faster germination of digested seeds supports the hypothesis of a legitimate mutualistic interaction between Austral parakeets and *** hypothesized that the passage through the disperser digestive tract might break physiological dormancy as differences in germinability between ingested and non-ingested *** results highlight the relevant role of endoz

关键词： seed dispersal Austral forest mutualism gut passage viability germination success germinability

Retrospective study of HIV drug resistance in Mexican children with vertically transmitted infection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2022年第7期18卷 505-510页

作者： Cristina de Jesus Herrera-Castillo Angelica Maldonado-Rodriguez Othon Rojas-Montes Ana Maria Cevallos joséguillermo Vazquez-Rosales Rosalia Lira Infectious Diseases Department Pediatrics Hospital"Silvestre Frenk Freund"National Medical Center"Siglo ⅩⅪ".Mexican Social Sccurity Instiute(IMSS).Mexico City.Mexico Infectious and Parasitie Dise ases Medical Research Unit Pediatrics Hospital"Silvestre Frenk Freund"National Medical Center“Siglo ⅩⅪ”Mexican Social Security Institute(IMSS).Col.Cuauhtemoc.Av.Cuauhtemoc 33006720 Mexico CityMexico Departament of Molecular Biology and Biotechnology Biomedical Research InstituteNational Autonomous University of MexicoUNAMMexico City.Mexico

According to World Health Organization(WHO)estimates,in 2020,there were 1.8 million human immunodeficiency virus(HIV)-infected children below 15 years old living with HIV and 150,000 children who acquired the infection[1].Every year,110,000 children die as a consequence of acquired immune deficiency syndrome-related causes[2].As in adults,optimal management of infected children depends on early diagnosis and treatment with antiretroviral drugs based on their viral genotype.

关键词： infection diagnosis drugs

Sweet syndrome and differentiation syndrome in a patient with acute promyelocytic leukemia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2015年第2期3卷 196-198页

作者： guillermo Solano-López Mar Llamas-Velasco Maria josé Concha-Garzón Esteban Daudén Department of Dermatology Hospital Universitario de la Princesa

The differentiation syndrome is an inflammatory reaction with increased capillary permeability that occurs in up to 25% of patients with acute promyelocytic leukemia treated with all-trans retinoic acid. A 50-year-old man with acute promyelocytic leukemia underwent chemotherapy with idarubicin and all-trans retinoic acid. On day +21 the patient developed pruritic prepatelar papules as well as several 10 mm subcutaneous nodules in both thighs accompanied by persistent fever. On the day +25 the patient presented with bilateral pulmonary crackles, infiltrates in the right lower lobe and severe hypotension which required dopamine infusion. Biopsy of one of the thighs nodules was performed. A Sweet syndrome associated to a differentiation syndrome was suspected. All-trans retinoic acid therapy was discontinued and dexamethasone was administered. In 48 h the patient showed remission of the fever and the infiltrates and the skin lesions acquired a residual aspect. It is debatable whether these two syndromes are distinct entities with common mechanisms or whether they are poles of the same spectrum. Dermatologists and hematologists must be aware of these two syndromes and its pathophysiologic association.

关键词： Differentiation syndrome Sweet syndrome Acute promyelocytic leukemia All-trans retinoic acid

Optimal Coordinated Operation of Distributed Static Series Compensators for Wide-area Network Congestion Relief

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 Modern Power Systems and Clean Energy 2022年第5期10卷 1374-1384页

作者： Camilo Andres Ordonez M Antonio Gomez-Exposito guillermo EVinasco M jose Maria Maza-Ortega IEEE Smart Wires Union CityUSA Department of Electrical Engineering University of SevilleSevillaSpain Interconexion Electrica SA Intercolombia Sevilla Spain

Relieving network congestions is a critical goal for the safe and flexible operation of modern power systems, especially in the presence of intermittent renewables or distributed generation. This paper deals with the real-time coordinated operation of distributed static series compensators(DSSCs) to remove network congestions by suitable modifications of the branch reactance. Several objective functions are considered and discussed to minimize the number of the devices involved in the control actions, the total losses or the total reactive power exchanged, leading to a non-convex mixed-integer non-linear programming problem. Then, a heuristic methodology combining the solution of a regular NLP with k-means clustering algorithm is proposed to get rid of the binary variables, in an attempt to reduce the computational cost. The proposed coordinated operation strategy of the DSSCs is tested on several benchmark systems, providing feasible and sufficiently optimal solutions in a reasonable time frame for practical systems.

关键词： Distributed static series compensation(DSSC) flexible AC transmission system(FACTS) mixed-integer non-linear programming(MINLP) wide-area network control

Design and Implementation of an Extended Collectives Library for Unified Parallel C

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2013年第1期28卷 72-89页

作者： Carlos Teijeiro guillermo L.Taboada Juan Tourio Ramón Doallo jos C.Mourio Damivn A.Mallón Brian Wibecan Computer Architecture Group University of A Corua Galicia Supercomputing Center Jlich Supercomputing Centre Institute for Advanced SimulationForschungszentrum Jlich Industry Standard Servers Group Hewlett-Packard Company

Unified Parallel C （UPC） is a parallel extension of ANSI C based on the Partitioned Global Address Space （PGAS） programming model, which provides a shared memory view that simplifies code development while it can take advantage of the scalability of distributed memory architectures. Therefore, UPC allows programmers to write parallel applications on hybrid shared/distributed memory architectures, such as multi-core clusters, in a more productive way, accessing remote memory by means of different high-level language constructs, such as assignments to shared variables or collective primitives. However, the standard UPC collectives library includes a reduced set of eight basic primitives with quite limited functionality. This work presents the design and implementation of extended UPC collective functions that overcome the limitations of the standard collectives library, allowing, for example, the use of a specific source and destination thread or defining the amount of data transferred by each particular thread. This library fulfills the demands made by the UPC developers community and implements portable algorithms, independent of the specific UPC compiler/runtime being used. The use of a representative set of these extended collectives has been evaluated using two applications and four kernels as case studies. The results obtained confirm the suitability of the new library to provide easier programming without trading off performance, thus achieving high productivity in parallel programming to harness the performance of hybrid shared/distributed memory architectures in high performance computing.

关键词： Unified Parallel C collective operation programmability partitioned global address space high performance computing

Neutral protamine hagedorn/regular insulin in the treatment of inpatient hyperglycemia: Comparison of 3 basal-bolus regimens

在线全文

学校读者我要写书评

暂无评论

World Journal of Diabetes 2017年第10期8卷 455-463页

作者： Dania Lizet Quintanilla-Flores joséGerardo González-González guillermo García-De la Cruz Héctor Eloy Tamez-Pérez Department of Internal Medicine 'Dr. José Eleuterio González' University HospitalUniversidad Autónoma de Nuevo León Endocrinology Service 'Dr. José Eleuterio González' University HospitalUniversidad Autónoma de Nuevo León School of Medicine Universidad Autónoma de Nuevo León Research Division School of MedicineUniversidad Autónoma de Nuevo León

AIM To compare the safety and efficacy or 3 basal-bolus regimens of neutral protamine hagedorn(NPH)/regular insulin in the management of inpatient *** We randomized 105 patients with blood glucose levelsbetween 140 and 400 mg/dL to a basal-bolus regimen of NPH insulin given once(n = 30), twice(n = 40) or three times(n = 35) daily, in addition to pre-meal regular insulin. Major outcomes included were differences in glycemic control, frequency of hypoglycemia and total insulin *** NPH insulin given in a once-daily regimen was associated with better glycemic control(58.3%) compared to twice daily(42.4%) and three times daily(48.9) regimens(P = 0.031). The frequency of hypoglycemia was similar between the three groups(2.0%, 0.7% and 1.2%, P = 0.21). The mean insulin dose at discharge was 0.48 ± 0.14 U/kg in the once-daily group compared to 0.69 ± 0.28 in the twice-daily, and 0.65 ± 0.20 in the three times daily regimens(P < 0.001).CONCLUSION NPH insulin administered in a once-daily regimen resulted in improvement in glycemic control with similar rates of hypoglycemia compared to a twice-daily and a three times-daily regimen. Further studies are needed to evaluate whether this regimen could be implemented in all hospitalized patients with hyperglycemia.

关键词： Neutral protamine hagedorn insulin Hospital hyperglycemia Basal-bolus regimen Type 2 diabetes mellitus Inpatient care units