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Grid-Connected PV Solar Energy Converter with Active and Reactive Power Control

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Journal of Energy and Power Engineering 2014年第2期8卷 331-342页

作者： roberto F. Coelho Artur Pagnoncelli Galbiatti Denizar Cruz martins INEP Power Electronics Institute Federal University of Santa Catarina Florian6polis (SC) 88040-970 Brazil

This work proposes a 12 kW three-phase grid-connected single stage PWM DC-AC converter destined to process the energy provided by a photovoltaic array composed of 57 KC200GT PV modules with high power factor for any solar radiation. The PWM inverter modeling and the control strategy, using dqO transformation, are proposed in order to also allow the system operation as an active power filter, capable to compensate harmonic components and react power generated by the non-linear loads connected to the mains grid. An input voltage clamping technique is proposed to impose the photovoltaic operation on the maximum power point. Simulation and experimental results are presented to validate the proposed methodology for grid connected photovoltaic generation system.

关键词： Active and reactive power dqO transformation grid-connected PV systems three-phase DC-AC PWM converter.

Curcumin in inflammatory bowel diseases:Cellular targets and molecular mechanisms

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BIOCELL 2023年第11期47卷 2547-2566页

作者： AMYLLY SANUELLY DA PAZ martins MARLA DE CERQUEIRA ALVES ORLANDO roberto PIMENTEL DE ARAÚJO FABIANA OLIVEIRA DOS SANTOS CAMATARI MARÍLIA OLIVEIRA FONSECA GOULART FABIANA ANDRÉA MOURA Rede Nordeste de Biotecnologia(RENORBIO) Instituto de química e BiotecnologiaUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Programa de Pós-graduação em Nutrição(PPGNUT) Faculdade de Nutrição(FANUT)Universidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Programa de Pós-Graduação em Química e Biotecnologia(PPGQB) Instituto de química e BiotecnologiaUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Colegiado de Nutrição Universidade de Pernambuco(UPE)Campus PetrolinaPernambuco56328-900Brasil Programa de Pós-Graduação em Ciências da Saúde(PPGCS) Instituto de Ciências da SaúdeUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Programa de Pós-graduação em Ciências Médicas(PPGCM) Faculdade de MedicinaUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil

Curcumin,a natural product,has exhibited promising effects in both animal models and clinical trials,interacting with a multitude of factors linked to Inflammatory Bowel Disease(IBD).These factors encompass cytokines,oxidative stress-associated enzymes,and modulation of the intestinal ***,curcumin has demonstrated therapeutic potential in animal models of colitis,wherein it exerts a negative regulatory influence on pivotal signaling pathways such as PI3/Akt,JAK/STAT,andβ-***,it inhibits the expression of proinflammatory enzymes and co-stimulatory molecules(including RANKL,ICAM-1,CD205,CD256,TLR4,among others),while curbing immune cell chemotaxis,thereby attenuating the characteristic neutrophil infiltration observed in *** facet of curcumin’s action involves its modulation of the intestinal ***,the microbiota itself contributes to beneficial biotrans formations of curcumin,thereby enhancing its effectiveness in IBD *** a clinical front,curcumin has demonstrated the ability to induce clinical and/or endoscopic remission without any reported toxic ***,curcumin warrants consideration as an adjunctive therapy in IBD *** clinical investigations should concentrate on meticulously evaluating curcumin’s impact on these precise therapeutic targets.

关键词： Curcuminoids Polyphenols CDAI scores Ulcerative colitis Antioxidant

Effects of Yerba Mate Consumption (Ilex paraguariensis) on Cardiac Remodeling in Rats

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Food and Nutrition Sciences 2024年第8期15卷 827-845页

作者： Carlos Eduardo Brochini de Paiva Thaíssa Baptista Brochini de Paiva Isabelle Tiburcio Pecin Ferreira Sandra Cristina Genaro Danilo Silva martins Santos Thaoan Bruno Mariano Robson Chacon Castoldi Rafael Stuani Floriano Julia Amanda Rodrigues Fracasso Lucas Pires Guarnier Marina Politi Okoshi Francis Lopes Pacagnelli Postgraduate Program in Health Sciences Unoeste Presidente Prudente Brazil Faculty of Medicine Unoeste Presidente Prudente Brazil Department of Physiotherapy Unoeste Presidente Prudente Brazil Department of Nutrition Unoeste Presidente Prudente Brazil Postgraduate Program in Science and Movement Unesp Rio Claro Brazil Postgraduate Program in Health Promotion University of Northern Paran (UNOPAR) Londrina Brazil School of Dentistry So Paulo State University (UNESP) Araatuba Brazil Department of Genetics Ribeiro Preto Medical School University of So Paulo USP Ribeiro Preto Brazil Internal Medicine Department Botucatu Medical School So Paulo State University (UNESP) Botucatu Brazil

This study investigated the effects of yerba mate consumption, a South American beverage, on cardiac remodeling in rats. For this purpose, 24 male Wistar rats were divided into Control Group (CG) which received filtered water and a standard diet, and Yerba Mate Group (YM), 6 g of Ilex paraguariensis in 100 ml water and the same diet, for 30 days. The YM group showed a reduction in final body weight and food consumption without altering weight gain. Regarding cardiac remodeling, the YM group exhibited a decrease in the right ventricle weight/final body weight ratio, suggesting cardiac atrophy, without affecting the atria and left ventricle. There was no change in cardiomyocyte area or nuclear fractal dimension in both groups. However, animals that consumed yerba mate showed increased collagen deposition and a smaller fractal dimension in the left ventricle. The consumption of yerba mate at room temperature for 30 days induced changes in cardiac remodeling, as evidenced by increased collagen deposition and alterations in fractal dimension in the left ventricle.

关键词： Tereré Ilex paraguariensis Yerba Mate Cardiac Remodeling Fractal Dimension Hypertrophy

Application of a validated HPLC-PDA method for the determination of melatonin content and its release from poly(lactic acid)nanoparticles

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Journal of Pharmaceutical Analysis 2017年第6期7卷 388-393页

作者： Leiziani Gnatkowski martins Najeh Maissar Khalil Rubiana Mara Mainardes Department of Pharmacy Universidade Estadual do Centro-Oeste/UNICENTRORua Simeao Camargo Varela de Sd 0385040-080 GuarapuavaPRBrazil

Melatonin is a natural hormone and with the advancement of age its production declines and thereby may result in some neurological disorders. Exogenous administration of melatonin has been suggested as a neuroprotective agent. Due to its low oral bioavailability, the loading of melatonin in polymeric nanoparticles could be an important tool to effectively use exogenous melatonin. The quantification of the incorporated drug within polymeric nanoparticles is an important step in nanoparticles characterization. An analytical method using high performance liquid chromatography equipped with photodiode array detector （HPLC-PDA） was developed and validated for melatonin determination in poly （lactic acid） nanoparticles obtained by a single emulsion-solvent evaporation technique. The melatonin in vitro release profile also was determined by the HPLC method. Mobile phase consisted of acetonitrile： water （65：35, v/v） pumped at a flow rate of 0.9 mL/min, in the isocratic mode and PDA detector was set at 220 nm. The method was validated in terms of the selectivity, linearity, precision, accuracy, robustness, limits of detection and quantification. Analytical curve was linear over the concentration range of 10-100 ~tg/mL, and limits of detection and quantification were 25.9 ng/mL and 78.7 ng/mL, respectively. The mean recovery for melatonin was 100.47% （RSD = 1.25%, n = 9）. In the intra- and inter- assay, the coefficient of variation was less than 2%. Robustness was proved performing changes in mobile phase, column temperature and flow rate. The method was suitable for the determination of melatonin encapsulation efficiency in poly（lactic acid） nanopartieles and for the evaluation of melatonin in vitro release profile.

关键词： High-performance liquid chromatography Validation Melatonin Polymeric nanoparticles

Combined Training in the Treatment of Type 2 Diabetes Mellitus: A Review

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Health 2017年第12期9卷 1605-1617页

作者： Cláudia Gomes Bracht Rodrigo Sudatti Delevatti Luiz fernando martins Kruel Universidade Federal do Rio Grande do Sul Porto Alegre Brazil Universidade Federal de Santa Catarina Florianópolis Brazil

This study aimed to review combined training (CT) effects on HbA1c levels in patients with T2DM. Searches were conducted in PubMed via MEDLINE and Google Scholar. Of the 14 selected studies, 11 found reductions in HbA1c levels. The interventions that performed both aerobic and resistance training in the same sessions were highlighted. In aerobic training, the best results were in the interventions between 30 and 45 minutes per session, with intensities between 60 and 80% of maximal parameters. In resistance training, the interventions with sets from 8 to 12 repetitions with intensities of 80% and 60% of 1RM respectively, or prescribed by maximal repetitions, were highlighted. We conclude that CT can result in better glycaemic control than AT and RT conducted alone.

关键词： Diabetes Combined Training Glycaemic Control HbA1c

Traction power substation balance and losses estimation in AC railways using a power transfer device through Monte Carlo analysis

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Railway Engineering Science 2022年第1期30卷 71-95页

作者： Vitor A.Morais Antonio P.martins Department of Electrical and Computer Engineering Faculty of EngineeringUniversity of PortoPorto 4200465Portugal

The high dynamic power requirements present in modern railway transportation systems raise research challenges for an optimal operation of railway electrification. This paper presents a Monte Carlo analysis on the application of a power transfer device installed in the neutral zone and exchanging active power between two sections. The main analyzed parameters are the active power balance in the two neighbor traction power substations and the system power losses. A simulation framework is presented to comprise the desired analysis and a universe of randomly distributed scenarios are tested to evaluate the effectiveness of the power transfer device system. The results show that the density of trains and the relative branch length of a traction power substation should be considered in the evaluation phase of the best place to install a power transfer device, towards the reduction of the operational power losses, while maintaining the two substations balanced in terms of active power.

关键词： Electric traction systems Monte Carlo analysis Power transfer device Power quality Railway power systems Smart railways

Analysis of long-term dependence phenomenon in Benue River flow process and its hypothesis testing

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Chinese Journal of Oceanology and Limnology 2008年第3期26卷 313-322页

作者： martins Y. OTACHE 李致家 Mohammad BAKIR State Key Laboratory of Hydrology-Water Resources ＆ Hydraulic Engineering Hohai University Nanjing 210098 China

In this paper, the long-term dependence phenomenon （the Hurst Effect） which characterizes hydrological and other geophysical times series is studied. The long-term memory is analysed for both daily and monthly streamflow series of the Benue River at Makurdi, Nigeria by using heuristic methods and testing specifically the null hypothesis of short-term memory in the monthly flow series. Results obtained by applying heuristic procedures indicated that there may be the presence of long-term memory component in mean daily flow series but there is no discernible reason to suspect the presence in both average monthly and maximum monthly flow series （extreme event）. Hypothesis testing was conducted by using original and modified versions of rescaled range statistic. When the modified rescaled range, which accounts for short-term memory in the series, is used, the null hypothesis is accepted for both the average monthly and maximum monthly flow series, indicating little or no probable presence of long-term memory in the series. An identical conclusion is also arrived at when second null hypothesis for independence of the monthly flow series is tested. Therefore, apart from the mean daily flow series, there is little evidence of long-term dependence in the Benue River streamflow series at Makurdi. However, considering the limited length of data used, the results are inconclusive.

关键词： Hurst exponent hydrological method time series river flow long memory Nigeria

Patient-derived iPSC models of Friedreich ataxia:a new frontier for understanding disease mechanisms and therapeutic application

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Translational Neurodegeneration 2023年第1期12卷 258-280页

作者： Saumya Maheshwari Gabriela Vilema-Enríquez Richard Wade-martins Department of Physiology Anatomy and GeneticsKavli Institute for Nanoscience DiscoveryUniversity of OxfordSouth Parks RoadOxford OX13QUUK

Friedreich ataxia(FRDA)is a rare genetic multisystem disorder caused by a pathological GAA trinucleotide repeat expansion in the FXN *** numerous drawbacks of historical cellular and rodent models of FRDA have caused difficulty in performing effective mechanistic and translational studies to investigate the *** recent discovery and subsequent development of induced pluripotent stem cell(iPSC)technology provides an exciting platform to enable enhanced disease modelling for studies of rare genetic *** iPSCs,researchers have created phenotypically relevant and previously inaccessible cellular models of *** models enable studies of the molecular mechanisms underlying GAA-induced pathology,as well as providing an exciting tool for the screening and testing of novel disease-modifying *** review explores how the use of iPSCs to study FRDA has developed over the past decade,as well as discussing the enormous therapeutic potentials of iPSC-derived models,their current limitations and their future direction within the field of FRDA research.

关键词： Friedreich ataxia Induced pluripotent stem cells Disease modelling Disease pathogenesis Drug development

Catalytic combustion of soot over Ru-doped mixed oxides catalysts

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Journal of Rare Earths 2014年第7期32卷 610-620页

作者： L.F.Nascimento R.F.martins O.A.Serra Department of Chemistry Faculdade de FilosofiaCiências e Letras de Ribeirao PretoUniversity of Sao PauloAv.Bandeirantes 3900CEP 14040-901 Ribeirao PretoSPBrazil

We employed modified substrates as outer heterogeneous catalysts to reduce the soot originating from the incomplete diesel combustion. Here, we proposed that ceria（CeO2）-based catalysts could lower the temperature at which soot combustion occurred from 610 oC to values included in the operation range of diesel exhausts（270–400 oC）. Here, we used the sol-gel method to synthesize catalysts based on mixed oxides（ZnO：CeO2） deposited on cordierite substrates, and modified by ruthenium nanoparticles. The presence of ZnO in these mixed oxides produced defects associated with oxygen vacancies, improving thermal stability, redox potential, sulfur resistance, and oxygen storage. We evaluated the morphological and structural properties of the material by X-ray diffraction（XRD）, Brumauer-emmett-teller method（BET）, temperature programmed reduction（H2-TPR）, scanning electron microscopy（SEM）, and transmission electron microscopy（TEM）. We investigated how the addition of Ru（0.5 wt.%） affected the catalytic activity of ZnO：CeO2 in terms of soot combustion. Thermogravimetric analysis（TG/DTA） revealed that presence of the catalyst decreased the soot combustion temperature by 250 oC, indicating that the oxygen species arose at low temperatures, which was the main reason for the high reactivity of the oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy（DRS） showed that the catalyst containing Ru on the mixed oxide-impregnated cordierite samples efficiently oxidized soot in a diesel stationary motor： soot emission decreased 80%.

关键词： soot combustion ceria mixed oxides ruthenium nanoparticles rare earths