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Multifunctional Nanostructured Materials Applied in Controlled Radiopharmaceuticals Release

Journal of Biomaterials and Nanobiotechnology 2012年第2期3卷 163-168页

作者： Raquel Cristina de sousa Azevedo Daniel Crístian Ferreira Soares ricardo geraldo de sousa Edésia Martins Barros de sousa Centro de desenvolvimento da Tecnologia Nuclear(CDTN)/CNEN Serviço de NanotecnologiaBelo HorizonteBrazil departa-mento de Engenharia Química Universidade Federal de Minas GeraisBelo HorizonteBrazil

The metaiodobenzylguanidine (MIBG) radiopharmaceutical, an analogue of norepinephrine, has been used to diagnose certain diseases in the cardiovascular system when radiolabeled with 123I. This radiopharmaceutical can also be used to treat tumors, such as neuroblastomas and pheochromocytomas, when radiolabeled with 131I. Its clinical use is often accompanied by a slow intravenous administration, where a significant dose of radiation can directly affect workers in nuclear medicine services. To overcome this problem, the incorporation and controlled release of radiopharmaceuticals from the matrix of mesoporous systems based on silica, such as SBA-15 and hybrid [SBA-15/P(N-iPAAm)], can lead to a significant reduction in radiation doses received by workers. In the present study, silica matrices SBA-15 and hybrid [SBA-15/P(N-iPAAm)] containing the radiopharmaceutical MIBG were prepared and physicochemically characterized through FTIR, SEM, and small angle X-ray diffraction techniques. The release profiles of MIBG from SBA-15 and [SBA-15/P(N-iPAAm)] were studied in a simulated body fluid (SBF) to evaluate their potential application as vehicles for controlled releases. Furthermore, in vitro studies were performed to assess the cytotoxicity of matrices as compared to human lung fibroblast cells (MRC-5). The results revealed that the amount of MIBG incorporated within the studied matrices was indeed quite different, showing that only the hybrid [SBA-15/P(N-iPAAm)] system allowed for a more adequate release profile of MIGB. Taking all results into consideration, it can be concluded that the hybrid matrix [SBA-15/P(N-iPAAm)] can be considered a potential alternative material for the controlled release delivery of radio-pharmaceuticals.

关键词： SAB-15 Hybrid[SBA-15/P(N-iPAAm)] MIGB Radiopharmaceutical Drug Release

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Synthesis and Characterization of Poly(D,L-Lactide-co-Glycolide) Copolymer

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Journal of Biomaterials and Nanobiotechnology 2012年第2期3卷 208-225页

作者： Cynthia D’Avila Carvalho Erbetta ricardo José Alves Jarbas Magalhaes Resende Roberto Fernando de Souza Freitas ricardo geraldo de sousa Polymer Science and Technology Laboratory Chemical Engineering DepartmentSchool of EngineeringFederal University of Minas GeraisBelo HorizonteBrazil Pharmaceutical Products department Pharmacy SchoolFederal University of Minas GeraisBelo HorizonteBrazil Chemical department Exact Sciences InstituteFederal University of Minas GeraisBelo HorizonteBrazil

The copolymer poly(D,L-lactide-co-glycolide) is one of the most interesting polymers for medical applications. This interest is justified by the fact that it is bioreabsorbable, biocompatible and non-toxic, while its degradation kinetics can be modified by the copolymerization ratio of the monomers. In this study, copolymers were synthesised at 175?C by opening the rings of the cyclic dimers of the D,L-lactide and glycolide monomers in the presence of stannous octoate initiator and lauryl alcohol co-initiator. The application of vacuum to the reaction medium, coupled with adequate stirring, is essential for obtaining good results. The following analytical techniques were used to characterise the synthesised copolymers: Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Both the input monomers and the reaction products were analysed. Important characteristics, such as melting temperature, glass transition temperature, thermal stability, chemical composition and the ratio of the monomers in the synthesised copolymer, were obtained from these analyses. These results helped to infer the absence of residual monomers in the synthesised copolymers.

关键词： PLGA Synthesis Characterization DSC TG NMR FTIR

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Rheological Study of Polymers Used as Viscosity Index Improvers for Automotive Lubricant Oils

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Journal of Modern Physics 2014年第12期5卷 1085-1093页

作者： Ana Paula Pena Almeida Ana Paula Lelis Rodrigues de Oliveira Cynthia D’ávila Carvalho Erbetta ricardo geraldo de sousa Roberto Fernando de Souza Freitas Maria Elisa Scarpelli Ribeiro e Silva Polymer Science and Technology Laboratory Chemical Engineering Department Engineering School Federal University of Minas Gerais Belo Horizonte Brazil

In this work, a rheological study of automotive lubricant oils, neutral light paraffinic (NLP) and neutral medium paraffinic (NMP), additivated with two commercial viscosity index improvers-VIIs, based on hydrogenated poly (isoprene-co-styrene), at different concentrations, was carried out. The study included the determination of the kinematic viscosity of the mixtures, the calculation of the viscosity indexes and their behavior when subjected to various rheometric experiments, including stress sweep, steady state flow, creep and recovery, and temperature ramp oscillatory tests. The obtained results showed the efficacy of the additives as viscosity index improvers, enabling a significant increase in the viscosity index of the pure oils at relatively low concentrations. The determination of the storage (G’) and of the loss (G”) moduli for the mixtures oil/VII additives showed a large predominance of the viscous effect over the elastic one. Except when under low shear stress, the mixtures showed a pseudoplastic behavior, with the flow curves being adjusted to fit the Ostwald-de-Waele model (Power Law), with negative flow behavior indexes.

关键词： Viscosity Index Improvers Automotive Lubricants Rheology Viscosity Index Polymer Additives

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Gastric Bypass with Long Pouch and Transit Bipartition for Endoscopic Access to the Remaining Stomach

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Surgical Science 2022年第8期13卷 353-366页

作者： Paulo Reis Esselin de Melo Marcella Giovana Gava-Brandolis Thonya Cruz Braga Danilo Fossalussa Minari ricardo Augusto Martins Bueno da Costa Jose geraldo Moraes Sampaio Neto Louise Flores Silva José Humberto Cardoso Resende Hospital Estadual Alberto Rassi Surgical Skills Coordinator Goi&#226nia Brazil UNIFAN Research Coordinator Aparecida de Goi&#226nia Brazil

Introduction: obesity has a complex and multifactorial etiology, difficult treatment and increasing incidence rates in recent decades. The treatment involves clinical and pharmacological approaches and, in case of lack of results, surgical interventions. Roux-en-Y gastric bypass (RYGB) is one of these surgical interventions in which the stomach is divided, creating a small pouch, and the remaining portion of the stomach become excluded and left without endoscopic access. Objective: to evaluate the results of modified RYGB with long pouch and endoscopic access to the remaining stomach. Materials and Methods: prospective clinical trial with sample selected among patients seen at the Alberto Rassi General State Hospital of Goiânia (HGG) and indicated for bariatric and metabolic surgery confirmed by the medical and multidisciplinary team. The study was conducted from January 2020 to August 2021. Clinical history and laboratory test results of the selected patients were collected through consultations with the medical and multidisciplinary team. Results: twelve participants were included in the study. Of these, 11 (91.7%) were women and the mean age was 46.3 years. The weight before surgery was 112.17 kg (92.00 - 150.00) and the Body Mass Index (BMI) was 44.89 (35.06 - 74.39). After 18 months of surgery, the mean weight was 80.77 kg (±11.92) and the mean BMI was 29.46 (±11.00), showing a significant reduction in both (p = 0.003 and p = 0.002, respectively). All patients underwent endoscopic evaluation of the pouch, remaining stomach and duodenum at 12 months postoperatively. The mean percentage of lost excess weight loss was 68.21%. Conclusion: We conclude that the proposed changes in RYGB (GBLP + GIB – Roux-en-Y gastric bypass with long pouch and gastrointestinal bipartition) did not compromise weight loss or control of type 2 diabetes and other comorbidities and proved to be a safe and effective alternative without gastroduodenal exclusion, enabling a better postop

关键词： Obesity Bariatric Surgery Metabolic Surgery Roux-En-Y Gastric Bypass

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Challenges in the chemotherapy of Chagas disease: Looking for possibilities related to the differences and similarities between the parasite and host

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World Journal of Biological Chemistry 2017年第1期8卷 57-80页

作者： Vitor Sueth-Santiago debora decote-ricardo Alexandre Morrot Celio geraldo Freire-de-Lima Marco Edilson Freire Lima Instituto Federal de Educacao Ciência e Tecnologia do Rio de JaneiroCampus Sao Goncalo Universidade Federal Rural do Rio de Janeiro Instituto de Ciências ExatasDepartamento de Química Universidade Federal Rural do Rio de Janeiro Instituto de VeterináriaDepartamento de Microbiologia e Imunologia Veterinária Universidade Federal do Rio de Janeiro

Almost 110 years after the first studies by Dr. Carlos Chagas describing an infectious disease that was named for him, Chagas disease remains a neglected illness and a death sentence for infected people in poor countries. This short review highlights the enormous need for new studies aimed at the development of novel and more specific drugs to treat chagasic patients. The primary tool for facing this challenge is deep knowledge about the similarities and differences between the parasite and its human host.

关键词： Trypanosoma cruzi Trans-sialidase Trypanothione reductase CYP51 Cruzipain 导管素

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Synthesis, Characterization, and Study of PLGA Copolymer <i>in Vitro</i>degradation

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Journal of Biomaterials and Nanobiotechnology 2015年第1期6卷 8-19页

作者： Anamaria Teodora Coêlho Rios Silva Barbara Camilla Oliveira Cardoso Maria Elisa Scarpelli Ribeiro e Silva Roberto Fernando Souza Freitas ricardo geraldo sousa Polymer Science and Technology Laboratory Chemical Engineering Department School of Engineering Federal University of Minas Gerais Belo Horizonte Brazil

The poly(lactic-co-glycolic acid), known as PLGA, is one of the main bioreabsorbable polymers used in the field of medicine today. This copolymer is widely applied in sutures, devices geared toward the controlled release of medication, and the guided regeneration of bone tissue as it presents a short degradation time. This work aimed to synthesize the 82/18 PLGA (expressed by the mass ratio of D,L-lactide and glycolide, respectively), to characterize and study the in Vitro degradation in the form of rods in phosphate buffer solution (PBS). The copolymer was synthesized by opening the cyclic dimer rings of the monomers D,L-lactide and glycolide, in the presence of the tin octanoate initiator and of the lauryl alcohol co-initiator. The characterization of the copolymer and the follow-up of its in vitro degradation were studied using: Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Infrared Molecular Absorption Spectroscopy with Fourier Transform (FTIR), Rheometry, and Scanning Electron Microscopy (SEM). Through these characterization techniques, it was possible to obtain the glass transition temperature, thermal stability, chemical composition, morphology, and molar mass of both the synthesized and the degraded copolymer. The molar mass of the synthesized copolymer was, approximately, 106 g·mol-1. The degradation rate of PLGA significantly increased from the 19th to the 28th day in PBS. After 28 days in PBS, the glass transition temperature and the molar mass reduced from 45°C to 17°C and from 1.5 × 106 g·mol-1?to 7.5 × 104?g·mol-1, respectively. The pH of the medium has a significant influence on the copolymer degradation profile. When it diminishes, it accelerates the degradation process, resulting in smaller PLGA polymer chains. This pH dependent degradation can be useful for drug release systems.

关键词： Synthesis Characterization In Vitro degradation PLGA

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Synthesis and PAMPA Permeability Assay of New Sulfonyl Hydrazone derivatives

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Journal of Biosciences and Medicines 2019年第9期7卷 111-120页

作者： Luiz Felipe Schmitz de Souza Tiago Tizziani Larissa Sens Dalila Venzke Inê s Maria Costa Brighente Moacir geraldo Pizzolatti ricardo José Nunes Laborató rio Estrutura e Atividade Departamento de Qu&iacute mica LEAT-CFM-UFSC Universidade Federal de Santa Catarina Campus Trindade Florian&oacute polis SC Brazil Laborató rio de Quí mica de Produtos Naturais Departamento de Qu&iacute mica LQPN-CFM-UFSC Universidade Federal de Santa Catarina Campus Trindade Florian&oacute polis SC Brazil

This work describes the synthesis of seven new sulfonyl hydrazones, which were proposed from the general structure of acyl hydrazones and 2,4-dinitrosulfonamides. Sulfonyl hydrazones are a class of compounds known to exhibit a wide range of biological activity. In this sense, the study of the pharmacokinetic properties of the bioactive molecules is of extreme importance;therefore, in this article the permeability of these compounds with in vitro PAMPA assay mimetizing the permeability through the gastrointestinal tract as well as lipophilicity through miLogP was investigated. All compounds presented good permeability results;it was possible to make a structure-activity relationship with the obtained results and a comparison between the results.

关键词： Sulfonyl Hydrazones PAMPA Permeability Organic Synthesis Medicinal Chemistry

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Rheological and Thermal Behavior of High-density Polyethylene (HDPE) at Different Temperatures

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Materials Sciences and Applications 2014年第13期5卷 923-931页

作者： Cynthia D’Avila Carvalho Erbetta Getúlio F. Manoel Ana Paula Lelis Rodrigues Oliveira Maria Elisa Scarpelli Ribeiro e Silva Roberto Fernando Souza Freitas ricardo geraldo sousa Polymer Science and Technology Laboratory Chemical Engineering Department Engineering School Federal University of Minas Gerais Belo Horizonte Brazil

In the present work, rheological properties of HDPE samples were measured at temperatures of 150°C, 190°C and 230°C. It was shown, by oscillatory tests, at low frequencies, that, for temperatures of 150°C and 190°C, there was a predominance of the viscous behavior over the elastic one. At 230°C, there was a predominance of the elastic contribution, and there was an increase of the molar mass compared with the ones obtained from the tests at 150°C and 190°C. The results obtained from the temperature ramp oscillatory test showed that, up to around 248°C, the viscous behavior prevailed, the opposite being observed at higher temperatures. At 230°C the sample showed significantly lower values of strain when compared with the ones observed at 150°C and 190°C. Oxidative induction time (OIT), melting point and degree of crystallinity were determined by differential scanning calorimetry (DSC). The DSC results and the rheological measurements showed a completely different behavior for the HDPE samples at 230°C compared with the 150°C and the 190°C ones, suggesting that HDPE, at the temperature of 230°C, underwent thermo-oxidative degradation with the initial predominance of crosslinking.

关键词： HDPE Rheology degradation DSC FTIR

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Justicia insularis Improves the in vitro Survival and development of Ovine Preantral Follicles Enclosed in Ovarian Tissue

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Journal of Pharmacy and Pharmacology 2017年第9期5卷 668-680页

作者： Gildas Tetaping Mbemya denise Damasceno Guerreiro Nathalie Jiatsa Donfacl~ Luciana Mascena Silv~ Luis Alberto Vieira Geovania Francisca Canafistula de sousa Benner geraldo Alves Aryele Pinto Izaguirry Francielli Weber Santos Phelix Bruno Telefo Otilia deusdenia Loiola Pessoa Johan Smitz Jose ricardo de Figueiredo Ana Paula Ribeiro Rodrigues Faculty of Veterinary (FA VET) State University of Ceara Fortaleza 60714903 Brazil Laboratory of Reproduction Biotechnology (Biotech) State of University of Pampa Uruguaiana 97500970 Brazil Laboratory of Biochemistry of Medicinal Plants Food and Nutritional Sciences Faculty of Science University of DschangDschang 3451381 Cameroon Laboratory of Phytochemical Analysis of Medicinal Plants (LAFIPLAN) Federal University of Cear6 Fortaleza 60020181 Brazil Follicle Biology Laboratory Center for Reproductive Medicine Brussels 1090 Belgium

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B-1 cells modulate the murine macrophage response to Leishmania major infection

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World Journal of Biological Chemistry 2017年第2期8卷 151-162页

作者： Angelica F Arcanjo Marise P Nunes Elias B Silva-Junior Monique Leandro Juliana Dutra Barbosa da Rocha Alexandre Morrot debora decote-ricardo Celio geraldo Freire-de-Lima Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Instituto Oswaldo Cruz FIOCRUZ Instituto de Microbiologia Paulo de Góes Universidade Federal do Rio de Janeiro Instituto de Veterinária Universidade Federal Rural do Rio de Janeiro

AIM To investigate the modulatory effect of B-1 cells on murine peritoneal macrophages infected with Leishmania major(L. major) in *** Peritoneal macrophages obtained from BALB/c andBALB/c XID mice were infected with L. major and cultured in the presence or absence of B-1 cells obtained from wild-type BALB/c mice. Intracellular amastigotes were counted, and interleukin-10(IL-10) production was quantified in the cellular supernatants using an enzymelinked immunosorbent assay. The levels of the lipid mediator prostaglandin E2(PGE2) were determined using a PGE2 enzyme immunoassay kit(Cayman Chemical, Ann Arbor, MI), and the number of lipid bodies was quantified in the cytoplasm of infected macrophages in the presence and absence of B-1 cells. Culturing the cells with selective PGE2-neutralizing drugs inhibited PGE2 production and confirmed the role of this lipid mediator in IL-10 production. In contrast, we demonstrated that B-1 cells derived from IL-10 KO mice did not favor the intracellular growth of L. *** We report that B-1 cells promote the growth of L. major amastigotes inside peritoneal murine macrophages. We demonstrated that the modulatory effect was independent of physical contact between the cells, suggesting that soluble factor(s) were released into the cultures. We demonstrated in our co-culture system that B-1 cells trigger IL-10 production by L. major-infected macrophages. Furthermore, the increased secretion of IL-10 was attributed to the presence of the lipid mediator PGE2 in supernatants of L. major-infected macrophages. The presence of B-1 cells also favors the production of lipid bodies by infected macrophages. In contrast, we failed to obtain the same effect on parasite replication inside L. major-infected macrophages when the B-1 cells were isolated from IL-10 knockout mice. CONCLUSION Our results show that elevated levels of PGE2 and IL-10 produced by B-1 cells increase L. major growth, as indicated by the number of parasites

关键词： Leishmania major Macrophages B-1 cells Interleukin-10 Prostaglandin E2 Infection

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