678 research outputs found

    Quality of seed potato tubers treated with paraquat and the development of a simplified methodology for paraquat residue detection

    Get PDF
    O objetivo desse trabalho foi avaliar a qualidade de tubĂ©rculos de batatas-semente (Solanum tuberosum) tratados com paraquat e desenvolver uma metodologia simplificada de detecção de resĂ­duos de herbicida. Dois ensaios foram realizados no LaboratĂłrio da CiĂȘncia das Plantas Daninhas do Centro Nacional de Pesquisa de hortaliças, BrasĂ­lia, DF. No experimento, tubĂ©rculos das cultivares Achat e Baronesa foram submersos em soluçÔes de 0 e 200 ppm de paraquat ou injetados com 0,5 ml de soluçÔes de 0 e 200 ppm do herbicida. O delineamento experimental foi inteiramente casualizado com 8 repetiçÔes e 12 tubĂ©rculos por parcela. Os tubĂ©rculos foram colocados em cĂąmara fria, apĂłs a aplicação com paraquat, para quebra da dormĂȘncia. ApĂłs a brotação dos tubĂ©rculos avaliou-se a qualidade interna dos mesmos, amostrando, posteriormente, 2 tubĂ©rculos de cada parcela para o plantio em vasos, sob condiçÔes de telado, para verificar possĂ­veis danos no crescimento das plantas oriundas dos tubĂ©rculos tratados. Os tratamentos de imersĂŁo nĂŁo provocaram, aparentemente, nenhum dano interno nos tubĂ©rculos, ou nem mesmo afetaram a nova geração, entretanto, os tubĂ©rculos injetados com paraquat foram severamente deteriorados e carbonizados, originando plantas bastante debilitadas. Esses resultados indicam que quando o paraquat for aplicado sob condiçÔes que favoreçam sua penetração ou translocação para o interior do tubĂ©rculo, atingindo os vasos e a polpa, pode danificĂĄ-lo severamente, prejudicar sua aparĂȘncia, qualidade de produção e reduzir o desenvolvimento da nova geração de plantas oriundas dos tubĂ©rculos contaminados . No segundo experimento, desenvolveu-se uma metodologia simplificada para detectar resĂ­duos de paraquat nos tubĂ©rculos atravĂ©s de colorimetria, visto que o paraquat Ă© reduzido a um radical de cor azul na presença de ditionito de sĂłdio (Na2S2O4) a 1% em meio bĂĄsico, a qual se intensifica Ă  medida que a concentração do produto aumenta. A metodologia simplificada desenvolvida permitiu detectar resĂ­duos de paraquat ao nĂ­vel de 0,06 ppm, indicando uma excelente aproximação, pois, o limite de tolerĂąncia do paraquat em tubĂ©rculos de batata Ă© de 0,2 ppm, normalmente, determinado pelo mĂ©todo analĂ­tico completo, que apresenta limites de detecção em torno de 0,01 ppm e recuperação acima de 70%. Uma avaliação qualitativa da concentração residual de produto nas amostras foi possĂ­vel atravĂ©s de leitura e comparaçÔes visuais entre os diferentes graus de cores desenvolvidas nas soluçÔes visuais entre os diferentes graus de cores desenvolvidas nas soluçÔes padrĂŁo e a cor desenvolvida na amostra, nĂŁo necessitando, portanto, das leituras colorimĂ©tricas, podendo ser feita inclusive no campo. Observou-se que a maioria do paraquat permaneceu na regiĂŁo de casca atĂ© o perĂ­odo de 4 semanas apĂłs a aplicação do paraquat.Seed potatoes tubers (Solanum tuberosum) of two cultivars (Achat and Baronesa) were treated with paraquat solutions to evalute the internal tuber quality and to detect its residue by a simplified methodology. Two experiments were carried out at the National Research Center on Vegetables, BrasĂ­lia, DF. In experiment one some tubers were immersed in 0 and 200 ppm of paraquat solutions and others were injected with 0,5 ml of 0 and 200 ppm solutions of the herbicide. Twelve tubers were used as plot in a complete randomized design with 8 replications. The internal tuber quality was evaluated after breaking dormancy and sprouting of ten tubers. Also, two tubers were sampled and put in 5 liter pots and grown under greenhouse conditions to observe if the herbicide would affect the growth of the new plant generation. The immersion treatments did not cause any internal damage to the tubers nor did they affect the new plant generation; however, tubers injected with paraquat were severely damaged (carbonization). Also, the next plant generation was affected and the surviving plants were small and not vigorus. These results indicate that paraquat can severely damage those tubers that absorbed and/or translocated the herbicide. In experiment two a simplified methodology to detect paraquat residue in the tubers was set up by colorimetric means. Paraquat was reduced with sodium dithionite (Na2S2O4) in basic solution to a blue radical ion whitch intensified its color with any increase in paraquat concentration. The development of this simplified methodology alowed the detection of paraquat residue above 0,06 ppm, indicating na excellent sensitivity and recovery in comparison with the residue analytical procedure of this herbicide, with a limit of detectability of about 0,01 ppm in crop samples of 200g. In addition to the quantitative determination of paraquat, this methodology allwos to determine qualitatively paraquat concentration by colour comparisons. Most of the paraquat residue was determined from potato skins up to 4 weeks after paraquat application

    Barriers to cardiac rehabilitation delivery in a low-resource setting from the perspective of healthcare administrators, rehabilitation providers, and cardiac patients

    Get PDF
    Background: Despite clinical practice guideline recommendations that cardiovascular disease patients participate, cardiac rehabilitation (CR) programs are highly unavailable and underutilized. This is particularly true in low-resource settings, where the epidemic is at its’ worst. The reasons are complex, and include health system, program and patient-level barriers. This is the first study to assess barriers at all these levels concurrently, and to do so in a lowresource setting. Methods: In this cross-sectional study, data from three cohorts (healthcare administrators, CR coordinators and patients) were triangulated. Healthcare administrators from all institutions offering cardiac services, and providers from all CR programs in public and private institutions of Minas Gerais state, Brazil were invited to complete a questionnaire. Patients from a random subsample of 12 outpatient cardiac clinics and 11 CR programs in these institutions completed the CR Barriers Scale. Results: Thirty-two (35.2%) healthcare administrators, 16 (28.6%) CR providers and 805 cardiac patients (305 [37.9%] attending CR) consented to participate. Administrators recognized the importance of CR, but also the lack of resources to deliver it; CR providers noted referral is lacking. Patients who were not enrolled in CR reported significantly greater barriers related to comorbidities/functional status, perceived need, personal/family issues and access than enrollees, and enrollees reported travel/work conflicts as greater barriers than non-enrollees (all p < 0.01). Conclusions: The inter-relationship among barriers at each level is evident; without resources to offer more programs, there are no programs to which physicians can refer (and hence inform and encourage patients to attend), and patients will continue to have barriers related to distance, cost and transport. Advocacy for services is needed. Keywords: Health care services, Cardiac rehabilitation, Cardiac care facilities, Attitude of health personnelYork University Librarie

    Electrochemical miRNA-34a-based biosensor for the diagnosis of Alzheimer’s disease

    Get PDF
    Alzheimer's disease (AD) is the most common dementia type and a leading cause of death and disability in the elderly. Diagnosis is expensive and invasive, urging the development of new, affordable, and less invasive diagnostic tools. The identification of changes in the expression of non-coding RNAs prompts the development of diagnostic tools to detect disease-specific blood biomarkers. Building on this idea, this work reports a novel electrochemical microRNA (miRNA) biosensor for the diagnosis of AD, based on carbon screen-printed electrodes (C-SPEs) modified with two gold nanostructures and a complementary anti-miR-34a oligonucleotide probe. This biosensor showed good target affinity, reflected on a 100 pM to 1 M linearity range and a limit of detection (LOD) of 39 pM in buffer and 94 aM in serum. Moreover, the biosensors response was not affected by serum compounds, indicating selectivity for miR-34a. The biosensor also detected miR-34a in the cell culture medium of a common AD model, stimulated with a neurotoxin to increase miR-34a secretion. Overall, the proposed biosensor makes a solid case for the introduction of a novel, inexpensive, and minimally invasive tool for the early diagnosis of AD, based on the detection of a circulating miRNA overexpressed in this pathology.This work was supported by 0624_2IQBIONEURO_6_E, 2IQBioneuro, Promotion of an R&I network in biological chemistry for the diagnosis and treatment of neurological diseases EP-INTERREG V Spain Portugal (POCTEP), and by Portuguese funds through FCT in the framework of the project PTDC/BTM-MAT/4156/2021. S.D.S acknowledges FCT (Fundação para a CiĂȘncia e a Tecnologia, I.P.) for her contract under the Norma TransitĂłria – DL57/2016/CP/CP1360/CT0013.info:eu-repo/semantics/publishedVersio

    The Membrane QmoABC Complex Interacts Directly with the Dissimilatory Adenosine 5â€Č-Phosphosulfate Reductase in Sulfate Reducing Bacteria

    Get PDF
    The adenosine 5â€Č-phosphosulfate reductase (AprAB) is the enzyme responsible for the reduction of adenosine 5â€Č-phosphosulfate (APS) to sulfite in the biological process of dissimilatory sulfate reduction, which is carried out by a ubiquitous group of sulfate reducing prokaryotes. The electron donor for AprAB has not been clearly identified, but was proposed to be the QmoABC membrane complex, since an aprBA–qmoABC gene cluster is found in many sulfate reducing and sulfur-oxidizing bacteria. The QmoABC complex is essential for sulfate reduction, but electron transfer between QmoABC and AprAB has not been reported. In this work we provide the first direct evidence that QmoABC and AprAB interact in Desulfovibrio spp., using co-immunoprecipitation, cross-linking Far-Western blot, tag-affinity purification, and surface plasmon resonance studies. This showed that the QmoABC–AprAB complex has a strong steady-state affinity (KD = 90 ± 3 nM), but has a transient character due to a fast dissociation rate. Far-Western blot identified QmoA as the Qmo subunit most involved in the interaction. Nevertheless, electron transfer from menaquinol analogs to APS through anaerobically purified QmoABC and AprAB could not be detected. We propose that this reaction requires the involvement of a third partner to allow electron flow driven by a reverse electron bifurcation process, i.e., electron confurcation. This process is deemed essential to allow coupling of APS reduction to chemiosmotic energy conservation

    Synthesis and cytotoxicity assessment of citrate-coated calcium and manganese ferrite nanoparticles for magnetic hyperthermia

    Get PDF
    Calcium-doped manganese ferrite nanoparticles (NPs) are gaining special interest in the biomedical field due to their lower cytotoxicity compared with other ferrites, and the fact that they have improved magnetic properties. Magnetic hyperthermia (MH) is an alternative cancer treatment, in which magnetic nanoparticles promote local heating that can lead to the apoptosis of cancer cells. In this work, manganese/calcium ferrite NPs coated with citrate (CaxMn1−xFe2O4 (x=0, 0.2, 1), were synthesized by the sol-gel method, followed by calcination, and then characterized regarding their crystalline structure (by X-ray diffraction, XRD), size and shape (by Transmission Electron Microscopy, TEM), hydrodynamic size and zeta potential (by Dynamic Light Scattering, DLS), and heating efficiency (measuring the Specific Absorption Rate, SAR, and Intrinsic Loss Power, ILP) under an alternating magnetic field. The obtained NPs showed a particle size within the range of 10 nm to 20 nm (by TEM) with a spherical or cubic shape. Ca0.2Mn0.8Fe2O4 NPs exhibited the highest SAR value of 36.3 W/g at the lowest field frequency tested, and achieved a temperature variation of ~7 °C in 120 s, meaning that these NPs are suitable magnetic hyperthermia agents. In vitro cellular internalization and cytotoxicity experiments, performed using the human cell line HEK 293T, confirmed cytocompatibility over 0–250 ”g/mL range and successful internalization after 24 h. Based on these studies, our data suggest that these manganese-calcium ferrite NPs have potential for MH application and further use in in vivo systems.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of CEB (UIDB/04469/2020), CBMA (UIDB/04050/2020) and CF-UM-UP (UIDB/04650/2020) units. R.G.D. Andrade and S.R.S. Veloso acknowledge FCT for the PhD grants 2020.05781.BD and SFRH/BD/144017/2019, respectively.info:eu-repo/semantics/publishedVersio

    Intergroup Emotions, Perceived Threats and Hostility against Foreigners: Comparing Brazil, Portugal, and Spain

    Get PDF
    This study analyzed whether hostility towards foreigners perceived as competitors in the labor market would be related to the perception of threat (symbolic and economic) and negative intergroup emotions. 270 people between 18 and 63 years participated. In Brazil (N = 89), mostly men (59%) and average age 32.5 years; In Portugal (N = 87), mostly men (56.3%) and average age 39.9 years; in Spain (N = 94), mostly women (53.2%) and average age of 32.8 years. The results (t-test, analysis of variance and multiple regressions) indicated that in Spain negative emotions are associated with less hostility towards immigrants; In Brazil, positive emotions are associated with hostile attitudes. In Portugal, the relationship between positive emotions and hostility is positive, but not signifi cant. The symbolic threat was the best predictor of hostility only in the Brazilian sample. Positive emotions predispose to a greater kindness towards foreigners in the three countries. The main conclusion of the study is that the economic crisis does not seem to be associated with the perception of competitiveness of foreigners in the local labor market and hostility towards this social group.O estudo analisou se a hostilidade para com estrangeiros percebidos como concorrentes no mercado de trabalho estaria relacionada com a percepção de ameaça (simbĂłlica e econĂŽmica) e as emoçÔes intergrupais negativas. Participaram 270 pessoas entre 18 e 63 anos, assim distribuĂ­das: Brasil (N = 89), idade mĂ©dia de 32.5 anos, maioria de homens (59%); Portugal (N = 87), idade mĂ©dia de 39.9 anos, maioria de homens (56.3%); e Espanha (N=94), idade mĂ©dia de 32.8 anos, maioria de mulheres (53.2%). Os resultados do Teste-t, anĂĄlise da variĂąncia e regressĂ”es mĂșltiplas indicaram que enquanto na Espanha emoçÔes negativas se associam a menos hostilidade para com imigrantes, no Brasil Ă© a expressĂŁo de emoçÔes positivas que se encontra associada a tais atitudes hostis. Em Portugal a relação entre emoçÔes positivas e hostilidade Ă© positiva, mas nĂŁo signifi cativa. A ameaça simbĂłlica foi o melhor preditor de hostilidade somente na amostra brasileira. EmoçÔes positivas predizem maior amabilidade para com estrangeiros nas amostras dos trĂȘs paĂ­ses. A principal conclusĂŁo do estudo Ă© que a crise econĂŽmica nĂŁo parece estar associada com a percepção de competitividade do estrangeiro no mercado de trabalho local e a hostilidade para com este grupo social.info:eu-repo/semantics/publishedVersio

    Doenças primĂĄrias da pele e manifestaçÔes cutĂąneas de doenças sistĂȘmicas em suĂ­nos

    Get PDF
    Skin diseases in pigs can negatively impact the production. They cause losses related to the death of the affected pigs, to the cost with the treatment, growth retardation and condemnations in the slaughterhouses. This study was developed to determine the frequency and describe the histopathological findings of skin diseases in pigs in different age groups through a retrospective study from 2006 to 2018. A total of 154 conclusive cases were analyzed, including skin restricted diseases (allergic dermatitis, exudative epidermitis, vesicular dermatitis, pityriasis rosea, swinepox, follicular cyst, papilloma and scrotal hemangioma) or skin lesions secondary to systemic diseases (erysipelas, porcine dermatitis and nephropathy syndrome [PDNS], bacterial septicemia and multiple hemorrhages without definite cause). The skin lesions were classified as bacterial (46.1%), viral (26.6%), allergic (12.3%), neoplastic (1.3%) and others (13.6%). Swine erysipelas was the most frequent diagnosis (47/154), followed by PDNS (23/154), allergic dermatitis (19/154) and exudative epidermitis (15/154). Vesicular dermatitis (9/154), pityriasis rosea (9/154), septicemia with cutaneous manifestations (9/154), swinepox (9/154) and multiple hemorrhages without definite cause (7/154) were also observed. Follicular cyst (3/154), hyperkeratosis without definite cause (2/154), papilloma (1/154), and scrotal hemangioma (1/154) were less frequently described. Of the conclusive diagnosis, age was reported in 138 cases, with the highest frequency of skin lesions observed at the inspection process during slaughter (56/138).As doenças de pele em suĂ­nos podem impactar negativamente a produção. Estas causam perdas relacionadas Ă  morte dos acometidos, a custo com tratamentos, atraso no crescimento e condenaçÔes nos frigorĂ­ficos. Este trabalho foi desenvolvido para determinar a frequĂȘncia e descrever os achados histopatolĂłgicos das doenças de pele em suĂ­nos nas diferentes faixas etĂĄrias, atravĂ©s de um estudo retrospectivo no perĂ­odo de 2006 a 2018. Foram analisados 154 casos conclusivos, incluindo as doenças restritas a pele (dermatites alĂ©rgicas, epidermite exsudativa, dermatite vesicular, pitirĂ­ase rĂłsea, varĂ­ola suĂ­na, cisto folicular, papiloma e hemangioma escrotal) e as secundĂĄrias a doenças sistĂȘmicas (erisipela, sĂ­ndrome dermatite nefropatia suĂ­na [SDNS], septicemia bacteriana e hemorragias mĂșltiplas de causa nĂŁo determinada). Estas foram classificadas em bacterianas (46,1%), virais (26,6%), alĂ©rgicas (12,3%), neoplĂĄsicas (1,3%) e outras (13,6%). A erisipela suĂ­na foi a enfermidade mais diagnosticada (47/154), seguida por SDNS (23/154), dermatite alĂ©rgica (19/154) e epidermite exsudativa (15/154). Observamos ainda dermatite vesicular (9/154), pitirĂ­ase rĂłsea (9/154), septicemia bacteriana com manifestaçÔes cutĂąneas (9/154), varĂ­ola suĂ­na (9/154) e hemorragias mĂșltiplas de causa nĂŁo determinada (7/154). Em menor nĂșmero, cisto folicular (3/154), hiperqueratose sem causa definida (2/154), papiloma (1/154) e hemangioma escrotal (1/154). Dos casos conclusivos, a idade foi informada em 138 casos, sendo a maior frequĂȘncia das lesĂ”es de pele observadas na linha de inspeção, durante o abate (56/138)

    Neurodifferentiation and neuroprotection potential of mesenchymal stromal cell-derived secretome produced in different dynamic systems

    Get PDF
    Parkinson’s disease (PD) is the second most common neurodegenerative disorder and is characterized by the degeneration of the dopamine (DA) neurons in the substantia nigra pars compacta, leading to a loss of DA in the basal ganglia. The presence of aggregates of alpha-synuclein (α-synuclein) is seen as the main contributor to the pathogenesis and progression of PD. Evidence suggests that the secretome of mesenchymal stromal cells (MSC) could be a potential cell-free therapy for PD. However, to accelerate the integration of this therapy in the clinical setting, there is still the need to develop a protocol for the large-scale production of secretome under good manufacturing practices (GMP) guidelines. Bioreactors have the capacity to produce large quantities of secretomes in a scalable manner, surpassing the limitations of planar static culture systems. However, few studies focused on the influence of the culture system used to expand MSC, on the secretome composition. In this work, we studied the capacity of the secretome produced by bone marrow-derived mesenchymal stromal cells (BMSC) expanded in a spinner flask (SP) and in a Vertical-Wheelℱ bioreactor (VWBR) system, to induce neurodifferentiation of human neural progenitor cells (hNPCs) and to prevent dopaminergic neuron degeneration caused by the overexpression of α-synuclein in one Caenorhabditis elegans model of PD. Results showed that secretomes from both systems were able to induce neurodifferentiation, though the secretome produced in the SP system had a greater effect. Additionally, in the conditions of our study, only the secretome produced in SP had a neuroprotective potential. Lastly, the secretomes had different profiles regarding the presence and/or specific intensity of different molecules, namely, interleukin (IL)-6, IL-4, matrix metalloproteinase-2 (MMP2), and 3 (MMP3), tumor necrosis factor-beta (TNF-ÎČ), osteopontin, nerve growth factor beta (NGFÎČ), granulocyte colony-stimulating factor (GCSF), heparin-binding (HB) epithelial growth factor (EGF)-like growth factor (HB-EGF), and IL-13. Overall, our results suggest that the culture conditions might have influenced the secretory profiles of cultured cells and, consequently, the observed effects. Additional studies should further explore the effects that different culture systems have on the secretome potential of PD.This work has been funded by la Caixa Foundation and Portuguese Foundation for Science and Technology (FCT) under the agreement LCF/PR/HP20/52300001; ICVS Scientific Microscopy Platform, member of the national infrastructure PPBI—Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122); by National funds, through the Foundation for Science and Technology (FCT)—project UIDB/50026/2020 and UIDP/50026/2020. CRM was supported by a Ph.D. scholarship from FCT and the company Stemmatters, Biotecnologia e Medicina Regenerativa SA (PD/BDE/127833/2016). Funding received by iBB-Institute for Bioengineering and Biosciences from FCT (UID/BIO/04565/2020) and through the project PTDC/EQU-EQU/31651/2017 is acknowledged. MAF was supported by a Ph.D. scholarship from FCT (SFRH/PD/BD/128328/2017). RC was supported by the EXOpro project (PTDC/EQU-QUE/31651/2017). JPS was supported by a Ph.D. scholarship from FCT and the company Bn’ML—Behavioral & Molecular Lab (PD/BDE/127834/2016). DS was supported by a Ph.D. scholarship from FCT and the company Stemmatters, Biotecnologia e Medicina Regenerativa S.A. (PD/BDE/135567/2018) JC was supported by a Ph.D. scholarship from FCT (SFRH/BD/5813/2020)
    • 

    corecore