检索结果-南通市图书馆

Model based current mode control design and experimental validation for a 3φ rectifier under unbalanced grid voltage conditions

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 2018年第4期6卷 777-790页

作者： P.R.MARTíNEZ-RODRIGEZ Jose M.SOSA Samuel ITURRIAGA-medina gerardo ESCOBAR gerardo VáZQUEZ-GUZMáN Andres A.VALDEZ-FERNáNDEZ School of Sciencies UASLP Laboratory of Electrical and Power Electronics ITESI School of Engineering Universidad Modelo

This paper addresses the control design and the experimental validation of a current mode control for a three phase voltage source rectifier. The proposed control law is able to fulfill the voltage regulation and the current tracking control objectives despite of unbalanced and distorted grid voltages. The proposed control law consists of two loops, which are referred as inner tracking loop and the outer voltage regulation loop. The inner loop is designed to provide damping to the system, which also includes and adaptive mechanism. The construction of the current reference is based on the positive component detection of thegrid voltage. Therefore, the current produced by the power rectifier is proportional to the fundamental component of the grid voltage, despite of the presence of unbalanced grid voltages. The voltage regulation loop is designed as a proportional-integral controller, which is aimed to regulate the DC output voltage to a desired level. Finally, experimental results are obtained in an experimental prototype of2 kW to evaluate the performance of the proposed controller.

关键词： Pulse-width modulation rectifier Power factor correction Positive-component Current mode control

Diversity, Endemism and Conservation of Ferns(Polypodiales) in the Mexican Mountain Component

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2015年第4期12卷 891-904页

作者： SANGINéS-FRANCO Celia LUNA-VEGA Isolda CONTRERAS-medina Raúl ESPINOSA David TEJERO-DíEZ José Daniel RIVAS gerardo Laboratorio de Biogeografía y Sistemática Departamento de Biología Evolutiva Facultad de Ciencias Universidad Nacional Autónoma de México (UNAM) Escuela de Ciencias Universidad Autónoma "Benito Juárez" de Oaxaca (UABJO) Av.Universidad s/n Ex Hacienda de Cinco Se?ores Oaxaca de Juárez CP 68120 Oaxaca México Facultad de Estudios Superiores Zaragoza Unidad Multidisciplinaria de Investigación Experimental ZaragozaUniversidad Nacional Autónoma de México (UNAM) Carrera de Biología Facultad de Estudios Superiores Iztacala Universidad Nacional Autónoma de México MéxicoAvenida de los Barrios Número 1 Colonia Los Reyes Iztacala Tlalnepantla CP 54090 Estado de México México Laboratorio de Biogeografía Acuática Departamento de Biología Comparada Facultad de Ciencias Universidad Nacional Autónoma de México (UNAM)

We analyzed the distributional patterns of95 selected species of leptosporangiate ferns inhabiting the Mexican Mountain Component, using grid-cells of one geographical degree as unit areas,applying endemism indices and richness and beta diversity *** data were obtained from several herbaria and specialized *** grid-cells appear to be important for fern species richness, as they contain 35 to 49 *** gridcells are located in the Sierra Madre Oriental(SMO),Trans-Mexican Volcanic Belt(TMVB) and the Sierra Madre del Sur(SMS).Mean richness by latitudinal belts of one degree showed that the belts with highest values are related to the TMVB and SMS.A total of 13grid-cells were recognized as important from theperspective of endemism; most of them are located also in the SMO, TMVB and *** richest gridcells coincided with one of the main centres of endemism for ferns obtained in this study, located in the convergence of the southern part of the SMO, the eastern portion of the TMVB and the northern part of the SMS, reflecting the high humidity existing on the mountain slopes facing the Gulf of *** important grid-cells recognized from richness and endemism analyses coincide with Mexican Natural Protected *** beta diversity analysis showed a low degree of similarity among grid-cells, implying a high species replacement, as the result of environmental heterogeneity occurring in the Mexican mountain *** the other hand, the spatial analysis suggested a pattern of phytogeographical regionalization comprising twomain areas: the Mexican Transition Zone and the Mexican Central *** play an important role in the Mexican biodiversity and contributing to the beta diversity of Mexico.

关键词： Biogeography Distributional patterns Leptosporangiate ferns Mexico

Validation of a preclinical dry eye model in New Zealand white rabbits during and following topical instillation of 1% ophthalmic atropine sulfate

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Animal Models and Experimental Medicine 2022年第3期5卷 266-273页

作者： Alejandra Sánchez-Ríos Elba Yadira Correa-Gallegos José Manuel medina-Espinoza Andrea Anaid Navarro-Sanchez Oscar Olvera-Montaño Leopoldo Baiza-Durán Patricia Muñoz-villegas Medical Affairs Department Laboratorios SophiaSA de CVZapopanJaliscoMexico

Background : The objective of this study was to validate an animal model for dry eye during and after the administration of 1% ophthalmic atropine sulfate(OAS) in New Zealand white(NZW) *** : OAS(1%) was applied three times per day to 30 eyes of 15 healthy NZW rabbits. Sacrifice, enucleation, and lacrimal gland removal took place on days 15, 21,and 30(OAS group). A second group(n = 5) was used as control. Clinical evaluations took place on days 3, 10, 15, 18, 21, 24 and 30. The primary endpoints were:Schirmer I test, tear break-up time(TBUT), and corneal fluorescein staining. As secondary endpoints, clinical changes including intraocular pressure, and histopathology were *** : While OAS was administered, the Schirmer I test showed a statistically significant reduction for OAS group versus control( p < 0.001), and versus basal production( p < 0.001). TBUT showed statistically significant differences between groups(days 3 and 10;p = 0.001) and versus basal values(day 3;p < 0.001). Fluorescein staining showed a statistically significant difference(day 3;p = 0.001). The most frequent clinical finding was conjunctival hyperemia(76.9% OAS vs. 20% control). For histopathology, all OAS subjects presented some degree of inflammation(86.7% minimal;13.3% mild) whereas the control presented only 30% minimal inflammation. Goblet cell density showed no *** : The effectiveness of the OAS dry eye model in NZW rabbits as reported in previous studies was confirmed, provided that the application of the drug is maintained throughout the intervention;it is not a viable model after OAS administration is suspended.

关键词： atropine sulfate dry eye rabbit model safety Schirmer I test TBUT

HP0953-hypothetical virulence factor overexpresion and localization during Helicobacter pylori infection of gastric epithelium

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2022年第29期28卷 3886-3902页

作者： Nancy K Arteaga-Resendiz gerardo E Rodea Rosa María Ribas-Aparicio Alma L Olivares-Cervantes Juan Arturo Castelán-Vega Joséde Jesús Olivares-Trejo Sandra Mendoza-Elizalde Edgar O López-villegas Christian Colín Pamela Aguilar-Rodea Alfonso Reyes-López Marcela Salazar García Norma Velázquez-Guadarrama Laboratorio de Investigación en Enfermedades Infecciosas Hospital Infantil de México Federico GómezMexico City 06720Mexico Posgrado en Biomedicina y Biotecnología Molecular Laboratorio de Producción y Control de BiológicosEscuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalMexico City 11340Mexico Laboratorio de Adquisición de Hierro Universidad Autónoma de la Ciudad MéxicoPosgrado Ciencias GenómicaMexico City 03100Mexico Laboratorio Central de Microscopía Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalMexico City 11340Mexico Centro de estudios económicos y sociales en salud Hospital Infantil de México Federico GómezMexico City 06720Mexico Laboratorio de Investigación en Biología del Desarrollo y Teratogénesis Experimental Hospital Infantil de México Federico GómezMexico City 06720Mexico

BACKGROUND The high prevalence and persistence of Helicobacter pylori(H. pylori) infection, as well as the diversity of pathologies related to it, suggest that the virulence factors used by this microorganism are varied. Moreover, as its proteome contains 340hypothetical proteins, it is important to investigate them to completely understand the mechanisms of its virulence and survival. We have previously reported that the hypothetical protein HP0953 is overexpressed during the first hours of adhesion to inert surfaces, under stress conditions, suggesting its role in the environmental survival of this bacterium and perhaps as a virulence *** To investigate the expression and localization of HP0953 during adhesion to an inert surface and against gastric(AGS) *** Expression analysis was performed for HP0953 during H. pylori adhesion. HP0953 expression at 0,3, 12, 24, and 48 h was evaluated and compared using the Kruskal-Wallis equality-of-populations rank test. Recombinant protein was produced and used to obtain polyclonal antibodies for immunolocalization. Immunogold technique was performed on bacterial sections during adherence to inert surfaces and AGS cells, which was analyzed by transmission electron microscopy. HP0953 protein sequence was analyzed to predict the presence of a signal peptide and transmembrane helices, both provided by the ExPASy platform, and using the GLYCOPP platform for glycosylation sites. Different programs, via, I-TASSER, RaptorX, and HHalign-Kbest, were used to perform three-dimensional *** HP0953 exhibited its maximum expression at 12 h of infection in gastric epithelium *** technique revealed HP0953 localization in the cytoplasm and accumulation in some peripheral areas of the bacterial body, with greater expression when it is close to AGS *** analysis revealed the presence of a signal peptide that interacts with the transmembrane region and then allows the release of the protein

关键词： Hypothetical protein HP0953 Adherence Helicobacter pylori Glycocalyx Virulence factor Persistence

Estimation of the Attitude in an Industrial Robot： An Unit Quaternion Approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

通讯和计算机（中英文版） 2012年第11期9卷 1287-1292页

作者： Salmeron-Quiroz Bemardino Benito Guerrero-Castellanos Jose Fermi villegas-medina gerardo Rodriguez-Paredes Salvador Antonio Lam-Farias Luis Faculty of Engineering Autonomous University of San Luis Potosi (UASLP) zipcode 78290 San Luis PotosL Mexico Mechatronics Department Autonomous University of Puebla (BUAP) Valsequillo Boulevard zipcode 72592 Puebla Mexico National Polytechnic Institute (IPN- SEPI ESIME UA) Av. De la Granjas 682 Azcapotzalco zipcode 02250 Mexico City Motors Department Volkswagen Mexico Mexico-Puebla Km 116 Puebla zipcode 72700 Mexico

Traditionally, the automotive industry has been the largest employer of robots, but their control is inline and programmed to follow planning trajectories. In this case, in the department motor"s test of Volkswagen Mexico a semi-autonomous robot is developed. To date, some critical technical problems must be solved in a number of areas, including in dynamics control. Generally, the attitude estimation and the measurement of the angular velocity are a requirement for the attitude control. As a result, the computational cost and the complexity of the control loop are relatively higher. This paper deals with the implementation of an cheap micro AHRS (attitude and heading reference system) using low-cost inertial sensors. In the present paper, the technique proposed is designed with attitude estimation and the prediction movement. With this approach, only the measurements of at least two non-collinear directional sensors are needed. Since the control laws are highly simple and a model-based observer for angular velocity reconstruction is not needed, the proposed new strategy is very suitable for embedded implementations. The global convergence of the estimation and prediction techniques is proved. Simulation with some robustness tests is performed.

关键词：工业机器人姿态估计四元数法预测技术单位动态控制姿态控制机器人开发

Successful Management of a Complicated Ulcer Caused by Autoimmune Vasculitis, with Sildenafil Citrate in a Patient with Primary Antiphospholipid Syndrome and Transient Steroid-Induced Diabetes Mellitus: A Case Report and Literature Review

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 Diabetes Mellitus 2014年第3期4卷 189-193页

作者： Fernando Grover-Paez Leonel Garcia-Benavides Ernesto German Cardona-Munoz Carlos gerardo Ramos-Becerra Jesus Ricardo Garcia-Corral Carlos Enrique medina-Garcia Guillermo Adrian Alanis-Sanchez Sylvia Elena Totsuka-Sutto Institute of Experimental and Clinical Therapeutics Department of PhysiologyUniversity Center of Health SciencesUniversity of GuadalajaraGuadalajaraMexico

Antiphospholipid syndrome (APS) is a prothrombotic condition that can affect both the venous circulation and the arterial system. The deep veins of the lower extremities and cerebral blood flow are the most common sites of venous and arterial thrombosis, respectively. Skin ulceration and gangrene may be associated with an active vasculitis in patients with APS. These kinds of ulcers are considered intractable because healing is difficult to achieve. Using steroids as immunesuppressant therapy is still a basic part of managing APS and vasculitis. Nevertheless, in the presence of steroid-induced diabetes mellitus, the priority is to achieve faster wound healing, because of the potential complications that can develop due to metabolic dysfunction and augmented vulnerability to infection. Until recently, there were few reports demonstrating the benefits of the use of adjuvant phosphodiesterase-5 inhibitors like sildenafil citrate in different clinical entities with courses like Raynaud’s phenomenon, scleroderma, and resistance to vasodilator therapy. We present the first report demonstrating the additional benefit of sildenafil citrate for the integration of grafts in a patient with steroid-induced diabetes and APS who had ulcers due to vasculitis resistant to the usual vasodilator therapy.

关键词： Autoimmune Vasculitis Sildenafil Citrate Steroid-Induced Diabetes Mellitus Primary Antiphospholipid Syndrome

Safety and Efficacy of Oral Mirodenafil in Mexican with Erectile Dysfunction

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 Clinical Medicine 2016年第9期7卷 628-638页

作者： Juan gerardo Reyes-García Noemí Santos-Caballero Francisco Javier Flores-Murrieta Sección de Estudios de Posgrado e Investigación Escuela Superior de Medicina Instituto Politécnico Nacional Ciudad de México Mexico Landsteiner Scientific S.A. de C.V. Ciudad de México Mexico Unidad de Investigación en Farmacología Instituto Nacional de Enfermedades Respiratorias “Ismael Cosio Villegas” Ciudad de México Mexico

Erectile dysfunction is treated with 5-phospodiesterase inhibitors as Mirodenafil, which has shown its efficacy and safety in Koreans, however;no information in other populations is available. An open clinical trial study was designed to evaluate the efficacy and safety in real life of a fixed-dose of Mirodenafil in Mexican patients with erectile dysfunction. Forty-seven male patients received a 100 mg tablet of Mirodenafil, during 12 weeks. Primary outcome efficacy measure was the percentage of male patients with successful intercourse. Secondary outcomes measures included patient satisfaction, mood and self-esteem level. Safety assessments included laboratory tests, vital signs, physical examination, 12-lead electrocardiogram recordings, and incidence of adverse events by patients. Oral administration of Mirodenafil improved in an 80% - 90% the number of successful intercourses from 7 to 84 days of treatment. Moreover, patients reported a significant increment in their sexual satisfaction, mood and self-esteem. Mirodenafil treatment did not modify vital signs nor anthropometric parameters during 84 days. Mild headache was the most frequent adverse event (17.0%) and there were no severe adverse events during pharmacological treatment. Data suggest that oral Mirodenafil is safety, well tolerated and effective in the Mexican population with erectile dysfunction.

关键词： Efficacy Erectile Dysfunction Mexicans Mirodenafil Safety

Oral Pharmacokinetics of Mirodenafil in Mexican Healthy Volunteers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pharmacology & Pharmacy 2014年第1期5卷 112-116页

作者： Miriam del Carmen Carrasco-Portugal Francisco Javier Flores-Murrieta Juan gerardo Reyes-García Noemí Santos-Caballero Landsteiner Scientific S.A. de C.V. México DF México Sección de Estudios de Posgrado e Investigación Escuela Superior de Medicina Instituto Politécnico Nacional México DF México Unidad de Investigación en Farmacología Insituto Nacional de Enfermedades Respiratorias “Ismael Cosio Villegas” México DF México Unidad de Investigación en Farmacología Insituto Nacional de Enfermedades Respiratorias “Ismael Cosio Villegas” México DF México Sección de Estudios de Posgrado e Investigación Escuela Superior de Medicina Instituto Politécnico Nacional México DF México

Mirodenafil is a 5-phosphodiesterase inhibitor that is currently marketed in Korea for the treatment of erectile dysfunction;however, no information in other populations is available. It has been described that Mirodenafil is metabolized by CYP3A4, a metabolic pathway in which interethnic differences have been reported. The purpose of this study was to characterize the oral pharmacokinetics of Mirodenafil in Mexicans. Seventeen male healthy volunteers were enrolled in this study. After an overnight fast, volunteers received an oral 100 mg dose and blood samples were collected at selected times during 24 h. Plasma was stored frozen and analyzed by an HPLC method. Pharmacokinetic parameters obtained were: Cmax 331.129 ± 32.689 ng/mL, tmax 1.574 ± 0.293 h, AUC24h 883.293 ± 104.088 ng·h/mL, AUC￥ 976.477 ± 108.812 ng·h/mL and t1/2 1.807 ± 0.171 h. Parameter values observed in this study are similar to those reported in Koreans. Since efficacy and safety studies of Mirodenafil have been conducted in Koreans, it is expected that dosage regime to employ in Mexicans should be similar to the approved for Korean population.

关键词： Erectile Dysfunction Healthy Volunteers Mexican Mirodenafil Pharmacokinetic

Isolation and Characterization of Mercury Resistant Trichoderma Strains from Soil with High Levels of Mercury and Its Effects on Arabidopsis thaliana Mercury Uptake

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Microbiology 2018年第7期8卷 600-613页

作者： JoséLuis Hernández-Flores Joségerardo Bernal Melo Andrés Cruz Hernández Miguel A.Ramos López Carlos Saldana Gutiérrez Sergio Romero Gomez Victor Pérez Moreno Rosa P.Calvillo medina JoséHumberto Valenzuela Soto Sergio Pacheco Hernández George H.Jones Sergio Casas Flores Juan Campos-Guillen Laboratorio de Bioseguridad y Análisis de Riesgo Departamento de Ingeniería Genética de PlantasCentro de Investigación y de Estudios Avanzados del IPNIrapuatoGto.México Facultad de Química Universidad Autónoma de QuerétaroCerro de las Campanas s/nQuerétaroQro.México Escuela de Agronomía Universidad De La Salle Bajíocampus Campestre.LeónGto.México Facultad de Ciencias Naturales Universidad Autónoma de QuerétaroAv.De las Ciencias S/NQuerétaroQro.México Centro de Investigación en Química Aplicada Blvd.Enrique Reyna Hermosillo No.140SaltilloCoahuilaMéxico Department of Biology Emory UniversityAtlantaGeorgiaUSA IPICYT División de Biología Molecular.Camino a la presa San JoséNo.2055Colonia Lomas 4a sección.C.P.San Luis PotosíMexico

Traditional mining activities are usually correlated with high levels of soil pollution, which is a major environmental concern. Extensive mining activities have taken place in the San Joaquin region in the State of Querétaro, México resulting in high levels of mercury soil pollution (up to 1532 ± 300 mg/kg). We isolated mercury-resistant fungal strains from the San Joaquin region soils and identified them through morphologic characteristics and ITS rDNA region sequence analysis. We determined that fungi isolated belong to the genus Trichoderma. All the isolates selected showed the ability to catalyze the volatilization of Hg. For air sampling, an active sampling device was constructed and using acid KMnO4 as an absorbent, the concentration of mercury in solution was determined through the cold vapor atomic absorption method. The results show mercury volatilization from the fungal species assay, with a maximum of 213.04 ± 32.6 μg/m3 while mycelium accumulation ranged from less than 17.5 ± 2.9 to 20.0 ± 3.4 μg/g. The fungal isolates were also evaluated for their ability to reduce mercury uptake in Arabidopsis thaliana. These observations suggest the utility of Trichoderma for the mobilization of mercury in those contaminated soils.

关键词： Volatilization Mercury Trichoderma Soil Bioremediation