A simple microfluidic device for the deformability assessment of blood cells in a continuous flow

Blood flow presents several interesting phenomena in microcirculation that can be used to develop microfluidic devices capable to promote blood cells separation and analysis in continuous flow. In the last decade there have been numerous microfluidic studies focused on the deformation of red blood cells (RBCs) flowing through geometries mimicking microvessels. In contrast, studies focusing on the deformation of white blood cells (WBCs) are scarce despite this phenomenon often happens in the microcirculation. In this work, we present a novel integrative microfluidic device able to perform continuous separation of a desired amount of blood cells, without clogging or jamming, and at the same time, capable to assess the deformation index (DI) of both WBCs and RBCs. To determine the DI of both WBCs and RBCs, a hyperbolic converging microchannel was used, as well as a suitable image analysis technique to measure the DIs of these blood cells along the regions of interest. The results show that the WBCs have a much lower deformability than RBCs when subjected to the same in vitro flow conditions, which is directly related to their cytoskeleton and nucleus contents. The proposed strategy can be easily transformed into a simple and inexpensive diagnostic microfluidic system to simultaneously separate and assess blood cells deformability.The authors acknowledge the financial support provided by PTDC/SAU-ENB/116929/2010 and EXPL/EMS-SIS/ 2215/2013 from FCT (Fundação para a Ciência e a Tecnologia), COMPETE, QREN and European Union (FEDER). R. O. Rodrigues, D. Pinho and V. Faustino acknowledge respectively, the PhD scholarships SFRH/BD/97658/2013, SFRH/BD/89077/2012 and SFRH/BD/99696/ 2014 granted by FCT. The authors would also like to thank Dr. Ângela Fernandes for providing the blood samples and Dr. Ricardo Calhelha for supplying the tissue culture medium used in this work.info:eu-repo/semantics/publishedVersio

Low cost microfluidic device for partial cell separation: micromilling approach

Several studies have already demonstrated that it is possible to perform blood flow studies in microfluidic systems fabricated by using low-cost techniques. However, most of these techniques do not produce microchannels smaller than 100 microns and as a result they have several limitations related to blood cell separation. Recently, manufacturers have been able to produce milling tools smaller than 100 microns, which consequently have promoted the ability of micromilling machines to fabricate microfluidic devices able to perform separation of red blood cells (RBCs) from plasma. In this work, we show the ability of a micromilling machine to manufacture microchannels with dimensions down to 30 microns. Additionally, we show for the first time the ability of the proposed microfluidic device to enhance the cell-free layer close to the walls, leading to perform partial separation of RBCs from plasma.The authors acknowledge the financial support provided by PTDC/SAU-ENB/116929/2010 and EXPL/EMSSIS/2215/2013 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER). RR and DP acknowledge, respectively, the PhD scholarships SFRH/BD/97658/2013 and SFRH/BD/89077/2012 attributed by FCT.info:eu-repo/semantics/publishedVersio

A new heligmonellid species (Nematoda) from oligoryzomys nigripes (Rodentia: Sigmodontinae) in the Atlantic Forest, Brazil

Fil: Souza, Joyce G.R.. Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios. Instituto Oswaldo Cruz. FIOCRUZ. Rio de Janeiro; BrazilFil: Digiani, María Celina. División Zoología Invertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Simäes, Raquel O.. Curso de Pós-GraduaçÆo em Ciências Veterinária. Universidade Federal Rural do Rio de Janeir; BrazilFil: Luque, José L.. Departamento de Parasitologia Animal. Universidade Federal Rural do Rio de Janeiro; BrazilFil: Rodrigues-Silva, Rosangela. Laboratório de Helmintos Parasitos de Vertebrados. Instituto Oswaldo Cruz. FIOCRUZ; BrazilFil: Maldonado, Arnaldo. Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios. Instituto Oswaldo Cruz. FIOCRUZ. Rio de Janeiro; Brazi

A rapid and low-cost nonlithographic method to fabricate biomedical microdevices for blood flow analysis

Microfluidic devices are electrical/mechanical systems that offer the ability to work with minimal sample volumes, short reactions times, and have the possibility to perform massive parallel operations. An important application of microfluidics is blood rheology in microdevices, which has played a key role in recent developments of lab-on-chip devices for blood sampling and analysis. The most popular and traditional method to fabricate these types of devices is the polydimethylsiloxane (PDMS) soft lithography technique, which requires molds, usually produced by photolithography. Although the research results are extremely encouraging, the high costs and time involved in the production of molds by photolithography is currently slowing down the development cycle of these types of devices. Here we present a simple, rapid, and low-cost nonlithographic technique to create microfluidic systems for biomedical applications. The results demonstrate the ability of the proposed method to perform cell free layer (CFL) measurements and the formation of microbubbles in continuous blood flow.The authors acknowledge the financial support provided by PTDC/SAU-BEB/105650/2008, PTDC/SAU-ENB/116929/2010, EXPL/EMS-SIS/2215/2013 and scholarship SFRH/BD/89077/2012 and SFRH/BD/97658/2013 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER).info:eu-repo/semantics/publishedVersio

Polymer microfluidic devices: an overview of fabrication methods

The amount of applications associated with microfluidic devices is increasing since the introduction of Lab-on-a-chip devices in the 1990s, especially regarding biomedical and clinical fields. However, in order for this technology to leave the fundamental research and become a day-life technology (e.g., as point-of-care testing), it needs to be disposable and reasonably less expensive. Polymers, due to their several advantages, such as easier microfabrication and low-cost, fill these needs. Several methods are reported regarding microfabrication and, thus, the main aim of the present work is to provide an overview of the most relevant microfabrication techniques found in literature employing polymers, clarifying also the main advantages and disadvantages of each technique and especially considering their cost and time-consumption. Moreover, a future outlook of low-cost microfabrication techniques and standard methods is provided

Haemocompatibility of iron oxide nanoparticles synthesized for theranostic applications: a high-sensitivity microfluidic tool

The poor heating efficiency of the most reported magnetic nanoparticles (MNPs), allied to the lack of comprehensive biocompatibility and haemodynamic studies, hampers the spread of multifunctional nanoparticles as the next generation of therapeutic bio-agents in medicine. The present work reports the synthesis and characterization, with special focus on biological/toxicological compatibility, of superparamagnetic nanoparticles with diameter around 18 nm, suitable for theranostic applications (i.e. simultaneous diagnosis and therapy of cancer). Envisioning more insights into the complex nanoparticle-red blood cells (RBCs) membrane interaction, the deformability of the human RBCs in contact with magnetic nanoparticles (MNPs) was assessed for the first time with a microfluidic extensional approach, and used as an indicator of haematological disorders in comparison with a conventional haematological test, i.e. the haemolysis analysis. Microfluidic results highlight the potential of this microfluidic tool over traditional haemolysis analysis, by detecting small increments in the rigidity of the blood cells, when traditional haemotoxicology analysis showed no significant alteration (haemolysis rates lower than 2 %). The detected rigidity has been predicted to be due to the wrapping of small MNPs by the bilayer membrane of the RBCs, which is directly related to MNPs size, shape and composition. The proposed microfluidic tool adds a new dimension into the field of nanomedicine, allowing to be applied as a highsensitivity technique capable of bringing a better understanding of the biological impact of nanoparticles developed for clinical applications.This work was financially supported by: Project POCI-01-0145-FEDER-006984 – Associate Laboratory J Nanopart Res (2016) 18:194 Page 15 of 17 194 123 LSRE-LCM funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalizac¸a˜o (POCI) – and by national funds through FCT - Fundac¸a˜o para a Cieˆncia e a Tecnologia. R.O.R. acknowledges the Ph.D. scholarship SFRH/BD/97658/2013 Granted by FCT. A.M.T.S acknowledges the FCT Investigator 2013 Programme (IF/01501/ 2013), with financing from the European Social Fund and the Human Potential Operational Programme. M.B. would like to thank ERDF (European Regional Development Fund) under grant PO Norte CCDR-N/ON.2 Programme. J.G. also thanks the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 600375.info:eu-repo/semantics/publishedVersio

Occurrence and diversity of yeast species isolated from fish feed and tambatinga gut

The present study aimed to identify yeasts species isolated from fish feed and the intestinal tracts of tambatinga fish (Colossoma macropomum × Piaractus brachypomum) cultivated in a Brazilian fish farm. Twenty tambatingas and 30 fish feed samples from different brands were acquired from two commercial establishments in the state of Piauí, Brazil. The sampled guts were divided into three equal parts, namely the anterior, medium and posterior portions, totaling 60 samples. Molecular identification was performed by PCR amplification and sequencing of the D1/D2 regions of the large rRNA subunit gene. Sixteen Candida nivariensis strains in the gut were identified. The fish feed samples showed a higher variability of yeast species, with the following species isolated: Hyphopichia burtonii (23.08%), Lodderomyces elongisporus (15.39%) and Trichosporon asahii (15.39%), Candida nivariensis (7.69%), C. orthopsilosis (7.69%), C. parapsilosis (7.69%), Rhodotorula minuta (7.69%), Sterigmatomyces elviae (7.69%), Cryptococcus liquefaciens (7.69%). Yeast found in feed, however, was not always isolated from tambatinga gut. Molecular identification allowed for the isolation of yeast species not previously reported in fish feed and gut samples.Fil: Pinheiro, Raizza Eveline E.. Universidade Federal Do Piaui;Fil: Dourado Rodrigues, Aline Maria. Universidade Federal Do Piaui; BrasilFil: Santos, Julliet Teixeira de O.. Universidade Federal Do Piaui; BrasilFil: Costa, Juliana de A.. Universidade Federal Do Piaui; BrasilFil: Pereyra, Carina Maricel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Torres, Adriana Mabel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; ArgentinaFil: Rosa, Carlos A.. Universidade Federal de Minas Gerais; BrasilFil: Santos, Ana Raquel de O.. Universidade Federal de Minas Gerais; BrasilFil: Muratori, Maria Christina S.. Universidade Federal Do Piaui; Brasi

Tecendo novos arranjos sociais: um estudo dos impactos de um empreendimento solidário na Comunidade Rural Córrego do Açude de Ituiutaba/MG

A emergência e a legitimação dos empreendimentos solidários vêm ocorrendo em diversos setores, tais como educação, saúde, transporte, todos com o objetivo de promover ações de interesse geral. A economia solidária e a economia social, conceitos que surgem no contexto europeu, particularmente, francês, fundamentam-se em experiências de iniciativas da comunidade capazes de gerar formas alternativas de ação pública, não se constituindo nem em uma forma de organização capitalista, nem em uma ação do Estado. Este artigo analisa a influência desses novos arranjos socioprodutivos no contexto da economia solidária que contribuem para a construção do processo de territorialização de uma comunidade sob o ponto de vista de sua identidade, de sua história e de suas relações sociais, conforme alguns parâmetros de avaliação presentes em projetos de economia solidária. Trata-se de uma pesquisa de natureza qualitativa com uso de recursos quantitativos. Utiliza-se de um estudo de caso da comunidade rural Córrego do Açude de Ituiutaba, Minas Gerais, a título de ilustração. A coleta de dados foi realizada por meio de entrevistas com membros da comunidade e documentos disponibilizados pela mesma. A partir da análise de quatro categorias, os resultados apontam que os fundamentos da economia solidária influenciam no território quanto aos aspectos de sua história, de suas relações sociais e de sua identidade