Smart Plastic Antibody Material for Hemoglobin Tailored by Silica Surface Imprinting and with Charged Binding Sites: Its use as Ionophore in Potentiometric Transduction

JORNADAS DE ELECTROQUÍMICA E INOVAÇÃO 2013Human hemoglobin (Hb) is a globular metalloprotein, present in the blood and involved in gas transport. Hb-associated disturbances are related to several diseases, such thalassemia, anemia, heart disease and leukemia, or to side-effects from other diseases, such as cancer. Overall, it is of great importance to know the concentration of Hb in the blood in many health-related conditions. There are many methods described in the literature for determining Hb. Most of these rely on antibody/antigen interactions, due to the high selectivity of the affinity reaction taking place between these biomolecules. However, the use of antibodies for Hb determination in routine clinical use is very expensive, due to the high cost of the material, the need for special handling and storage, and the non-reusability. These constraints may be limited by replacing natural antibodies by plastic receptors, obtained by molecular imprinting procedures. Thus, this work describes a novel smart plastic antibody material (SPAM) by surface imprinting technique for the detection of Hb and its application to design small, portable and low cost potentiometric devices. The SPAM material was obtained by linking Hb to silica nanoparticles and allowing its subsequent interaction with different vinyl monomers, of different chemical functions and ionic charges. Control materials were designed in parallel to assess the ability of establishing stereochemical recognition of Hb and the effect of the kind/charge of the monomers employed. Scanning Electron Microscopy analysis confirmed the surface modification of the silica material used for imprint. All materials were mixed with PVC/plasticizer and applied as selective membranes in potentiometric transduction. Suitable emf variations were detected only for selective membranes having a SPAM material and a charged lipophilic anionic additive. All control materials were unable to produce a potentiometric response. Overall, good features were obtained for SPAM-based selective membranes carrying an anionic lipophilic additive. In HEPES buffer of pH 5, limits of detection were 43.8μg/mL for a linear response after 83.8μg/mL with a cationic slope of +40.4mV/decade. Good selectivity was also observed against other coexisting biomolecules. The analytical application was conducted successfully, showing accurate and precise results

Data-Driven Modeling of the Cellular Pharmacokinetics of Degradable Chitosan-Based Nanoparticles

Nanoparticle drug delivery vehicles introduce multiple pharmacokinetic processes, with the delivery, accumulation, and stability of the therapeutic molecule influenced by nanoscale processes. Therefore, considering the complexity of the multiple interactions, the use of data-driven models has critical importance in understanding the interplay between controlling processes. We demonstrate data simulation techniques to reproduce the time-dependent dose of trimethyl chitosan nanoparticles in an ND7/23 neuronal cell line, used as an in vitro model of native peripheral sensory neurons. Derived analytical expressions of the mean dose per cell accurately capture the pharmacokinetics by including a declining delivery rate and an intracellular particle degradation process. Comparison with experiment indicates a supply time constant, τ = 2 h. and a degradation rate constant, b = 0.71 h−1. Modeling the dose heterogeneity uses simulated data distributions, with time dependence incorporated by transforming data-bin values. The simulations mimic the dynamic nature of cell-to-cell dose variation and explain the observed trend of increasing numbers of high-dose cells at early time points, followed by a shift in distribution peak to lower dose between 4 to 8 h and a static dose profile beyond 8 h

Analysis of entrepreneurial propensity of students from the Viseu pole of Portuguese Catholic University

Este artigo pretende mostrar a importância do ensino superior na promoção do empreendedorismo. Assim, começa-se com uma análise teórica dos conceitos de empreendedorismo e de empreendedor e dos principais motivos que conduzem ao empreendedorismo, bem como dos obstáculos que o dificultam. Salienta-se também a importância que o ensino superior tem na promoção do empreendedorismo. Faz-se, por fim, uma breve evolução histórica da educação para o empreendedorismo no ensino superior e do que tem sido feito em Portugal nesta área. Em termos metodológicos, apresentam-se os resultados de um estudo efetuado com 348 alunos do Pólo de Viseu da Universidade Católica Portuguesa. Este estudo teve como principal objetivo conhecer a propensão empreendedora dos seus alunos. Os resultados obtidos neste estudo sugerem que os alunos têm pouca tendência empreendedora, o que se poderá dever aos receios e às dificuldades em desenvolver um negócio próprio, assim como a alguns fatores que condicionam a criação e o sucesso de uma empresa. Assim, é fundamental evidenciar a importância do empreendedorismo, quer para os indivíduos, quer para a sociedade, e, por isso, é indispensável fomentar a sua promoção, sobretudo junto da comunidade escolar.This article aims to show the importance of higher education in promoting entrepreneurship. So, we start with a theoretical analysis of the concepts of entrepreneurship and entrepreneur and the main reasons that lead to entrepreneurship, such as the obstacles to it. Also highlight the importance that higher education has to promote entrepreneurship, and, finally, a brief historical development of entrepreneurship education in higher education and what has been done in this area in Portugal. In methodological terms, we present the results of a study conducted with 348 students from Viseu pole of the Portuguese Catholic University. This study aimed to know the entrepreneurial propensity of their students. The results of this study suggest that students have little entrepreneurial trend, which could be due to the fears and difficulties in developing their own business, as well as some factors that influence the creation and success of a company. Thus, it is crucial to highlight the importance of entrepreneurship, both for individuals and for society, and therefore it is essential to foster its promotion especially among the school community.info:eu-repo/semantics/publishedVersio

Large differences in gene expression responses to drought and heat stress between elite barley cultivar scarlett and a spanish landrace

23 Pags.- 6 Tabls.- 8 Figs. Copyright © 2017 Cantalapiedra, García-Pereira, Gracia, Igartua, Casas and Contreras-Moreira. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forms is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Drought causes important losses in crop production every season. Improvement for drought tolerance could take advantage of the diversity held in germplasm collections, much of which has not been incorporated yet into modern breeding. Spanish landraces constitute a promising resource for barley breeding, as they were widely grown until last century and still show good yielding ability under stress. Here, we study the transcriptome expression landscape in two genotypes, an outstanding Spanish landrace-derived inbred line (SBCC073) and a modern cultivar (Scarlett). Gene expression of adult plants after prolonged stresses, either drought or drought combined with heat, was monitored. Transcriptome of mature leaves presented little changes under severe drought, whereas abundant gene expression changes were observed under combined mild drought and heat. Developing inflorescences of SBCC073 exhibited mostly unaltered gene expression, whereas numerous changes were found in the same tissues for Scarlett. Genotypic differences in physiological traits and gene expression patterns confirmed the different behavior of landrace SBCC073 and cultivar Scarlett under abiotic stress, suggesting that they responded to stress following different strategies. A comparison with related studies in barley, addressing gene expression responses to drought, revealed common biological processes, but moderate agreement regarding individual differentially expressed transcripts. Special emphasis was put in the search of co-expressed genes and underlying common regulatory motifs. Overall, 11 transcription factors were identified, and one of them matched cis-regulatory motifs discovered upstream of co-expressed genes involved in those responses.This work was funded by DGA - Obra Social La Caixa [grant number GA-LC-059-2011] and by the Spanish Ministry of Economy and Competitiveness [projects AGL2010-21929, RFP-2012-00015-00-00 AGL2013-48756-R and AGL2016-80967-R]. Carlos P. Cantalapiedra is funded by [grant BES-2011-045905 linked to project AGL2010-21929].Peer reviewe

The Role Of Videolaparoscopy In The Diagnostic And Therapeutic Approach Of Nonpalpable Testis.

Evaluate the results from the first 5 years of experience with laparoscopy for diagnosis and treatment of nonpalpable testes. Medical records of 51 patients submitted to laparoscopic testicular exploration, during a 5-year period, were retrospectively analyzed. Patients' mean age was 65.7 months (median = 48) on the first procedure. The youngest patient was 10 months and the oldest was 14 years old on the first surgery. Twenty-four (47%) patients presented nonpalpable testes bilaterally, 7 (14%) only at the right side and 20 (39%) at the left, totaling 75 testicular units assessed. Patients who had their testes palpated after anesthetic induction were excluded from the study, and in all other cases, surgical management was based on the testicular position and viability. During the post-operative follow-up, surgical success was classified as palpable testis in scrotal sac, with adequate consistency and volume. Nine (12%) testes were not localized, but their vessels and deferent duct were atrophic. Two (3%) testes were intra-abdominal and atrophic, and 2 (3%) gonads, in the same patient, had a dysmorphic aspect. Nineteen (25%) testicular units were located close to the internal inguinal ring (peeping testes) and, in 22 (29%) units, the spermatic vessels and deferent duct penetrated the internal inguinal ring. Eight (10%) testes were located at a distance of less than 2 cm from the internal inguinal ring and 13 (17%) at a distance greater than 2 cm. The 2 intra-abdominal atrophic testes were removed. Inguinotomy was performed in a total of 41 (54%) cases, reaching a surgical success of 89%. Laparoscopic orchiopexy in one stage, without vascular ligation, was performed in 9 (12%) testes, which presented a distance of less than 2 cm from the internal inguinal ring, also with a surgical success index of 89%. Orchiopexy in 2 stages, with ligation of the spermatic vessels, was performed in 13 (17%) testicular units located at a distance greater than 2 cm from the internal inguinal ring, reaching 77% of good results. Videolaparoscopy is a safe and effective method for diagnosis and treatment of nonpalpable testis.29345-51; discussion 351-

Temporal variability of diazotroph community composition in the upwelling region off NW Iberia.

Knowledge of the ecology of N2-fixing (diazotrophic) plankton is mainly limited to oligotrophic (sub)tropical oceans. However, diazotrophs are widely distributed and active throughout the global ocean. Likewise, relatively little is known about the temporal dynamics of diazotrophs in productive areas. Between February 2014 and December 2015, we carried out 9 one-day samplings in the temperate northwestern Iberian upwelling system to investigate the temporal and vertical variability of the diazotrophic community and its relationship with hydrodynamic forcing. In downwelling conditions, characterized by deeper mixed layers and a homogeneous water column, non-cyanobacterial diazotrophs belonging mainly to nifH clusters 1G (Gammaproteobacteria) and 3 (putative anaerobes) dominated the diazotrophic community. In upwelling and relaxation conditions, affected by enhanced vertical stratification and hydrographic variability, the community was more heterogeneous vertically but less diverse, with prevalence of UCYN-A (unicellular cyanobacteria, subcluster 1B) and non-cyanobacterial diazotrophs from clusters 1G and 3. Oligotyping analysis of UCYN-A phylotype showed that UCYN-A2 sublineage was the most abundant (74%), followed by UCYN-A1 (23%) and UCYN-A4 (2%). UCYN-A1 oligotypes exhibited relatively low frequencies during the three hydrographic conditions, whereas UCYN-A2 showed higher abundances during upwelling and relaxation. Our findings show the presence of a diverse and temporally variable diazotrophic community driven by hydrodynamic forcing in an upwelling system

New Quantum-Dot-Based Fluorescent Immunosensor for Cancer Biomarker Detection

Cancer antigen 15-3 (CA 15-3) is a biomarker for breast cancer used to monitor response to treatments and disease recurrence. The present work demonstrates the preparation and application of a fluorescent biosensor for ultrasensitive detection of the cancer antigen CA 15-3 protein tumor marker using mercaptopropionic-acid-functionalized cadmium telluride (CdTe@MPA) quantum dots (QDs) conjugated with CA 15-3 antibodies. First, the QDs were synthesized by the hydrothermal route, resulting in spherical nanoparticles up to 3.50 nm in diameter. Subsequently, the QD conjugates were characterized by Fourier transform infrared spectroscopy (FTIR), UV absorption, and fluorescence. The interaction between the conjugates and the protein was studied by fluorescence spectroscopy in buffer and in 10-fold diluted commercial human serum. Calibration in spiked serum samples gave a detection limit of 0.027 U/mL, 1000-fold lower than the clinical limit for CA 15-3 (25 U/mL to 30 U/mL), indicating that this is an ultrasensitive technique. In addition, a rapid response was obtained within 10 min. The biosensor was selective in the presence of the interfering serum proteins BSA, CEA, and CA-125, with a maximum interference of 2% for BSA. The percent recovery was close to 100% with maximum relative standard deviation (RSD%) values of 1.56. Overall, the developed CA 15-3 biosensor provides a simple and sensitive method for ultrasensitive monitoring of breast cancer, as well as the ability to detect other molecules of interest in human serum matrices.This research was funded by Fundação para a Ciência e Tecnologia, I.P, grant number 2022.09032.PTDCinfo:eu-repo/semantics/publishedVersio