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Melting behavior and globular microstructure formation in semi-solid CoCrCuxFeNi high-entropy alloys

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Journal of Materials Science & Technology 2020年第17期52卷 207-217页

作者： Kaio Niitsu Campo Caio Chaussêde freitas leonardo Fanton Rubens Caram University of Campinas School of Mechanical EngineeringSPBrazil

High-entropy alloys can be compelling raw materials for semi-solid *** the present study,the influence of the Cu content on the melting behavior and semi-solid microstructure of CoCrCuxFeNi(x=0,1,2,3)alloys was ***-melted samples were cross-rolled at room temperature and then isothermally treated at 1175℃in the semi-solid state for 300 *** characterization showed that the alloys containing Cu were formed by two fcc ***,the increase in Cu content also led to an increase in the volumetric fraction of the Cu-rich *** solidification,this phase,which is the last to form,nucleates and epitaxially grows on the Cu-lean *** the studied CoCrCuFeNi alloys exhibited the same melting *** Cu-rich phase melts at approximately 1120℃,whereas the Culean phase melts at approximately 1350℃,providing a suitable processing temperature range of more than 200℃.The semi-solid microstructures were considerably refined and globular regardless of the alloy composition,being suitable for semi-solid ***,each fcc phase exhibited roughly the same composition under the different processing *** Cu content in the Cu-lean phase was approximately 10 at.%,while Co,Cr,Fe,and Ni were in an approximately equiatomic ***,the Cu content was between 80 at.%and 86 at.%in the Cu-rich *** isothermal treatment of the CoCrCu3FeNi alloy at a higher temperature(1300℃)only caused the globules to *** conclusion,this work showed that these alloys can be potential candidates for semi-solid processing.

关键词： Semi-solid processing Thixoforming High-entropy alloys Microstructure

The Use of Solid State NMR to Evaluate the Carbohydrates in Commercial Coffee Granules

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Food and Nutrition Sciences 2011年第4期2卷 350-355页

作者： Regina freitas Nogueira Elisangela Fabiana Boffo Maria Inês Bruno tavares leonardo AMoreira Leila Aley tavares Antonio Gilberto Ferreira Departamento de Química da Universidade Federal de Sao CarlosSao CarlosBrasil Institutito de Macromoléculas Universidade Federal do Rio de JaneiroRio de JaneiroBrasil Escola Técnica Federal de Minas GeraisBrasil

Coffee brings many health benefits due to its chemical constituents. Based on this information, it is essential to know the main chemical compounds from coffee granules;the intermolecular interaction among the coffees compounds and the molecular components homogeneity. In this study six types of roasted commercial coffee were evaluated by solid state nuclear magnetic resonance (NMR), employing carbon-13 (13C) and hydrogen (1H) nucleus. Carbon-13 was analyzed applying high field NMR techniques, such as: magic angle spinning (MAS);magic angle spinning with cross-polariza- tion (CPMAS) and magic angle spinning with cross-polarization and dipolar dephasing (CPMASDD). The hydrogen was evaluated via relaxation times. Proton spin-lattice relaxation time in the rotating frame was deter-mined through the carbon-13 decay, during the variable contact-time experiment, using high field NMR. Proton spin-lattice relaxation time was determined through the inversion-recovery pulse sequence, using low field NMR. Considering all NMR results, it was concluded that the major coffee compounds are: a) triacilglycerides, which constitute the mobile region in the granule coffee and b) Carbohydrates such as: polysaccharides and fibers that belong to the rigid domain. These constituents belong to different molecular mobility domain, although they have strong intermolecular interactions due to the granule organization.

关键词： Solid State NMR Coffee

Characterization of porous cobalt hexacyanoferrate and activated carbon electrodes under dynamic polarization conditions in a sodium-ion pseudocapacitor

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Journal of Energy Chemistry 2021年第3期30卷 53-62页

作者： Bruno Morandi Pires Willian Goncalves Nunes Bruno Guilherme freitas Francisca Elenice Rodrigues Oliveira Vera Katic Cristiane Barbieri Rodella leonardo Morais Da Silva Hudson Zanin Advanced Energy Storage Division Manufacturing CroupCarbon Sci-Tech LabsCenter for Innovation on New EnergiesUniversity of CampinasCampinas 13083-852SPBrazil Brazilian Synchrotron Light Laboratory(LNLS/Brazilian Center of Energy and Materiab(CNPEM)) Campinas 13083-970SPBrazil Department of Chemistry Laboratory of Fundamental and Applied ElectrochemistryFederal University of Jequitinhonha and Mucuri's VatleyAlto dajacuba 39100-000Diamantina-MGBrazil

We report here the activated carbon and cobalt hexacyanoferrate composite,which is applied as the electrode materials in symmetric supercapacitors containing a 1.0 M Na_(2)SO_(4) aqueous *** novel material combines high specific surface area and electrochemical stability of activated carbon with the redox properties of cobalt hexacyanoferrate,resulting in maximum specific capacitance of 329 F g^(-1) with large voltage working window of 2.0 *** studies indicated that cobalt hexacyanoferrate introduces important pseudocapacitive properties accounting for the overall charge-storage process,especially when I<0.5 A g^(-1).At lower gravimetric currents(e.g.,0.05 A g^(-1))and up to 1.0 V,the presence of cobalt hexacyanoferrate improves the specific energy for more than 300%.In addition,to better understanding the energy storage process we also provided a careful investigation of the electrode materials under dynamic polarization conditions using the in situ Raman spectroscopy and synchrotron light Xray diffraction *** complementary findings were obtained in these *** believe that this novel electrode material is promising for applications regarding the energy-storage process in pseudocapacitors with long lifespan properties.

关键词： Operando studies Raman XRD synchrotron light Cobalt hexacyanoferrate Activated carbon High specific capacitance

Treatment of Bullfrog Farming Wastewater in a Constructed Wetland

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Journal of Water Resource and Protection 2017年第6期9卷 578-589页

作者： Fernanda de freitas Borges Lúcia Helena Sipaúba tavares Laboratory of Limnology and Plankton Production S&#227o Paulo State University—UNESP Aquaculture Center Jaboticabal Brazil

The aim of this study was to install and assess the efficiency of a constructed wetland for wastewater treatment from bullfrog farming (Lithobates catesbeianus) at fattening growth phase. Water detention time was not controlled since wastewater input flow varied according to the biomass of animals maintained in stalls. The study was divided into two phases, with higher and lower bullfrog biomass respectively for phase I and II. A higher removal of nitrite, biochemical oxygen demand, and thermotolerant coliforms was observed at phase I whereas a higher removal of turbidity, nitrate, total phosphorus, total suspended solids, total dissolved solids, and chlorophyll a occurred at phase II. Wastewater treatments using constructed wetland systems with high organic load require a higher water detention time for a better load removal. The treatment effect was positive since this wastewater flowed directly into fishponds or streams, which might promote eutrophication. Thus, wastewater treatment is essential to minimize the impact caused by frog farming on receiving water bodies, promoting the sustainability of this activity in Brazil.

关键词： Biomass Eutrophication Lithobates catesbeianus Nutrient Removal Water Quality

Raman probing carbon&aqueous electrolytes interfaces and molecular dynamics simulations towards understanding electrochemical properties under polarization conditions in supercapacitors

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Journal of Energy Chemistry 2021年第9期30卷 279-292页

作者： Rafael Vicentini leonardo M.Da Silva Débora V.Franco Willian G.Nunes Juliane Fiates Gustavo Doubek Luís F.M.Franco Renato G.freitas Cristiano Fantini Hudson Zanin Advanced Energy Storage Division Carbon Sci-Tech LabsUniversity of CampinasAv Albert Einstein 400CampinasSP 13083-852Brazil Department of Chemistry Federal University of Jequitinhonha and Mucuri’s ValleyRodovia MGT 367km 5835000Alto da Jacuba39.100-000 DiamantinaMGBrazil Advanced Energy Storage Division Center for Innovation on New EnergiesLaboratory of Advanced BatteriesSchool of Chemical EngineeringUniversity of Campinas(UNICAMP)CampinasSP 13083-852Brazil Department of Chemistry Federal University of Mato GrossoICET-UFMT78060-900 CuiabáMTBrazil Departamento de Física ICExUniversidade Federal de Minas GeraisBelo HorizonteMG 31270-901Brazil

Raman probing of carbon electrode and electrolyte under dynamic conditions is performed here using different aqueous electrolytes to elucidate the fundamental events occurring in electrochemical supercapacitor during charge–discharge *** areal capacitance ranges from 1.54 to 2.31μF cm^(-2)μm and it is determined using different *** findings indicate that the Helmholtz capacitance governs the overall charge-storage process instead of the space charge(quantum)capacitance commonly verified for HOPG electrodes in the range of~3 to 7μF cm^(-2).Molecular dynamics simulations are employed to elucidate the origin of the reversible Raman spectral changes during the charge–discharge processes.A correlation is verified between the reversible Raman shift and the surface excesses of the different ionic species.A theoretical framework is presented to relate the effect of the applied potential on the Raman shift and its correlation with the surface ionic *** is proposed that the Raman shift is governed by the interaction of solvated cations with graphite promoted by polarization *** is the first time that a comparative study on different aqueous electrolyte p H and cation ion size has been performed tracking the Raman spectra change under dynamic polarization conditions and contrasting with comprehensive electrochemistry and dynamic molecular simulations *** study shines lights onto the charge-storage mechanism with evidence of Kohn anomaly reduction in the carbon electrode during the reversible adsorption/desorption and insertion/extraction of ionic species.

关键词： Defect reorganization in graphite Surface excess of charge Operando Raman studies Electrical double-layer capacitors

Distinct T helper cell-mediated antitumor immunity:T helper 2 cells in focus

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Cancer Pathogenesis and Therapy 2023年第1期1卷 76-86页

作者： Rafael Cardoso Maciel Costa Silva Marcela freitas Lopes leonardo Holanda Travassos Laboratory of Immunoreceptors and Signaling Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de Janeiro 21941-902Brazil Laboratory of Immunity Biology George DosReis Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de Janeiro 21941-902Brazil

The adaptive arm of the immune system is crucial for appropriate antitumor immune *** is generally accepted that clusters of differentiation 4^(+)(CD4^(+))T cells,which mediate T helper(Th)1 immunity(type 1 immunity),are the primary Th cell subtype associated with tumor *** this review,we discuss evidence showing that antitumor immunity and better prognosis can be associated with distinct Th cell subtypes in experimental mouse models and humans,with a focus on Th2 *** aim of this review is to provide an overview and understanding of the mechanisms associated with different tumor outcomes in the face of immune responses by focusing on the(1)site of tumor development,(2)tumor properties(i.e.,tumor metabolism and cytokine receptor expression),and(3)type of immune response that the tumor initially ***,we discuss how low-tolerance organs,such as lungs and brains,might benefit from a less tissue-destructive immune response mediated by Th2 *** addition,Th2 cells antitumor effects can be independent of CD8^(+)T cells,which would circumvent some of the immune escape mechanisms that tumor cells possess,like low expression of major histocompatibility-I(MHC-I).Finally,this review aims to stimulate further studies on the role of Th2 cells in antitumor immunity and briefly discusses emerging treatment options.

关键词： Cancer Immunology Adaptive immunity Immunotherapy Immunogenetics Antitumor immune response

Antibacterial activity and inhibition against Staphylococcus aureus NorA efflux pump by ferulic acid and its esterified derivatives

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Asian Pacific Journal of Tropical Biomedicine 2021年第9期11卷 405-413页

作者： Patrícia Gonçalves Pinheiro Gilvandete Maria Pinheiro Santiago Francisco Erivaldo freitas da Silva Ana Carolina Justino de Araújo Cícera Rejane tavares de Oliveira Priscilla Ramos freitas Janaína Esmeraldo Rocha JoséBezerra de Araújo Neto Maria Milene Costa da Silva Saulo Relison Tintino Irwin Rose Alencar de Menezes Henrique Douglas Melo Coutinho JoséGalberto Martins da Costa Departamento de Química Biológica Programa de Pos-Graduação em Química BiológicaUniversidade Regional do Cariri–URCACrato–CEBrazil Programa de Pós-Graduação em Química Centro de CiênciasUniversidade Federal do Ceará–UFCFortaleza–CEBrazil

Objective:To evaluate the inhibitory activity of ferulic acid and four of its esterified derivatives(methyl,ethyl,propyl,and butyl)against resistance mechanisms in Staphylococcus aureus ***:Ferulic acid derivatives were obtained by esterification with methanol,ethanol,propanol,and butanol,and then characterized by hydrogen and carbon-13 nuclear magnetic resonance *** minimum inhibitory concentrations(MIC)of ferulic acid and its esterified derivatives,ethidium bromide,and norfloxacin were obtained using the microdilution test,while the efflux pump inhibition test was conducted by examining reduction in the MICs of norfloxacin and ethidium *** docking was also carried out using the Schrodinger Suite 2015 molecular modeling software.A three-dimensional model of NorA efflux pump was generated using *** best scoring model was used as a receptor for ligand-receptor ***:The methyl and butyl ester derivatives did not demonstrate significant antimicrobial ***,a significant synergic effect was evidenced when norfloxacin was combined with the ethyl and propyl esterified *** docking study demonstrated favorable energy of interaction between ferulate derivatives and NorA,and amino acid residues TYR57,TYR58,and LEU255 were present commonly in stabilizing all *** PCA analysis corroborated the docking hypothesis that the lipophilic character and hydrogen bond interactions were the most relevant characteristics involved with NorA *** pharmacokinetic parameters of ferulic acid derivatives showed good ADMET properties,demonstrating that they can be easily absorbed and have no effect or inhibit the cytochrome P450 enzyme complex,revealing their potential as drug ***:This study provides strong evidence that the molecular basis for this activity is potentially due to the NorA efflux pump.

关键词： Ferulic acid Esterified derivatives Efflux pump Staphylococcus aureus Resistance mechanisms

Incorporation of Nano-Zinc Oxide in Lamellar Zirconium Phosphate: Synthesis and Characterization

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Materials Sciences and Applications 2023年第6期14卷 346-361页

作者： Danielle Mattos Mariano Daniela França Silva freitas Gerson Alberto Valencia Albitres Luis Claudio Mendes Maria Ines Bruno tavares Instituto de Macromoléculas Professora Eloisa Mano Centro de Tecnologia Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil

In order to provide ultraviolet barrier, antifungal and antibacterial properties, nano-zinc oxide (ZnO) was added to lamellar zirconium phosphate (ZrP). The phosphate was synthesized via reaction of zirconium oxychloride octahydrate and phosphoric acid following its chemical modification with Jeffamine and nano-ZnO. Diffractometric, morphological, thermal, structural and relaxometric evaluations were conducted. Fourier transform infrared spectroscopy (FTIR) revealed increase of the area between 4000 - 3000 cm-1 due to the formation of ionic specie PO? +NH3-[C-(H)(CH3)-CH2-O-(C-(H)(CH3)-CH2-O)8-(CH2-CH2-O-CH3)] and nano-ZnO particles. Wide-angle X-ray diffraction indicated that intercalation of Jeffamine was successful. Thermogravimetry confirmed that nano-ZnO particle forced the expulsion of Jeffamine outside ZrP galleries. Scanning electron microscopy evidenced the Jeffamine intercalation and sample heterogeneity. Hydrogen molecular relaxation indicated the increase of molecular rigidity owing to the formation of ionic specie and the addition of nano-ZnO particles. It was postulated that a multifunctional and miscellaneous material constituted by as prepared ZrP, some delaminated ZrP platelets and nano-ZnO particles was achieved. The material has potential for usage as filler in polymeric composites.

关键词： Lamellar Zirconium Phosphate Jeffamine Nano-Zinc Oxide Intercalation

Impact of Drug-Drug Interaction between CDK4/6 Inhibitors and Proton Pump Inhibitors on Survival Outcomes in the Treatment of Metastatic Breast Cancer—Real World Data from a Portuguese Center

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Journal of Cancer Therapy 2022年第5期13卷 266-274页

作者： Joana Reis Inês Costa Mariana Costa Ana Valente Catarina Almeida Marta freitas Cláudia Caeiro Catarina Fernandes Nuno tavares Miguel Barbosa Centro Hospitalar SÃ O JOÃ O E.P.E. Porto Portugal

Introduction: Proton pump inhibitors (PPi) are widely prescribed, including in patients undergoing treatment for advanced breast cancer (ABC). Due to the pharmacokinetic characteristics of the CDK4/6 inhibitor (Ci) palbociclib a drug interaction with PPi was hypothesized. It was shown in a retrospective study that this association was an independent predictive factor for worse progression-free survival (PFS). Objective: To verify the impact of concomitant administration of PPi with Ci on overall survival (OS) and PFS. Material and Methods: This is a retrospective cohort study of patients treated with Ci for HR+HER2-ABC in the period from Feb/2017 to Aug/2020. SPSS software was used for data processing. Univariate analysis was done by the Kaplan-Meier method and log-rank test, and multivariate analysis by COX regression. P-value < 0.05 was considered significant. Results: 80 patients were included. The median age at diagnosis of ABC was 56 years (25 - 75). Treatment with Ci was 1st line for ABC in 68.8%. Choice of Ci was palbociclib in 73.8% (n = 59) and ribociclib in 26.3% (n = 21). The hormone partner was a nonsteroidal aromatase inhibitor in 45.0%, and fulvestrant in 55.0% of cases. 37.5% of patients were on PPi, and 70.0% of them were during the entire treatment (23.3% omeprazole, 73.4% pantoprazole, 3.3% others). Patients taking concomitant PPi and Ci had lower OS (OS-3 years 42.6% vs. 63.4%, p = 0.254) and PFS (PFS med 15 m. vs. 21 m., p = 0.733), although with no statistically significant difference. Discussion: In the sample, there was a numerical difference, without the statistical significance in the use of PPi in the survival of patients under Ci. This difference could be more evident with a longer follow-up and a larger sample size. This study intends to alert to the growing importance of checking for drug interactions. Polymedication, advanced age and the presence of several comorbidities are real problems in patients with ABC. Conclusion: Real-world dat

关键词： Drug Interaction Survival Impact Advanced Breast Cancer CDK4/6 Inhibitors Proton Pump Inhibitors