Advanced search


Knowledge area




14 results, page 1 of 2

Fabrication of highly perfusable gelatin-methacryloyl (GelMA) constructs using flow-based strategies

GRISSEL TRUJILLO DE SANTIAGO (2020)

https://orcid.org/0000-0001-9230-4607

One of the most important challenges when engineering tissues in vitro is the creation of viable thick constructs. The diffusion of gas and nutrients severely limits the size of engineered constructs. Therefore, the incorporation of perfusable lumen structures within thick engineered tissues is needed for enabling gas exchange, perfusion of nutrients, and waste removal down to the depth of the tissue. Current biofabrication techniques used to create perfusable networks in thick 3D constructs are limited in resolution and control, and they require sophisticated or expensive tools.

In this work, we propose a simple technique to develop perfusable hydrogel constructs based on the use of a 3D flow-based biofabrication technique, namely the mini Journal Bearing (mJB), and by employing sacrificial inks. Through the action of regular flows induced in a mJB and the flow-advection of two different hydrogels, we created constructs with an internal sacrificial structure. We used gelatin methacryloyl (GelMA) as a permanent hydrogel matrix, and a drop (100 µL) of gelatin as a fugitive ink/bioink. Here we present a thorough characterization of the microarchitecture and porosity of these constructs. Especially, we demonstrated how permeability increased within these constructs. Additionally, aiming to mimic the architectural complexity of natural tissues, we added nanotopographical cues to our constructs by the incorporation of elongated flexuous plant viruses, namely Turnip Mosaic Virus (TuMV).

We conducted our in vitro experiments using myoblasts cells as a biological model and characterized their biological response through time. We fabricated three different types of cell-laden-constructs: GelMA with suspended cells, GelMA with a gelatin ink loaded with cells, and GelMA with a gelatin ink loaded with cells and TuMV. Cells were able to grow faster and for longer in GelMA/gelatin constructs than in pristine-GelMA constructs. While an intricate network of cells was developed after 28 days of culture within permeabilized GelMA/gelatin constructs, only surface proliferation was observed in dense constructs made exclusively with GelMA. The use of GelMA/gelatin-TuMV had an evident morphological effect on cell attachment and proliferation. TuMV 3D meshes providing additional scaffolding within the lumina. While myoblast alignment was strongly evident in GelMA/gelatin where cells adhered mainly to the lamellae walls, in GelMA/gelatin-TuMV constructs, cells alignment was attenuated by interaction with the 3D micromesh of TuMV.

Maestra en Nanotecnología

Master thesis

BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA CELULAR CULTIVO DE TEJIDOS CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS AGRONOMÍA TÉCNICAS DE CULTIVO INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS NUTRIENTES

Development and characterization of a high hydrosoluble food ingredient using extruded whole chickpea flour and sequential alcalase® and α-amylase treatment

ESTHER PEREZ CARRILLO ERICK HEREDIA OLEA Sergio Román Othón Serna Saldivar (2020)

Chickpea is an adequate source of proteins and starch which can be used to develop new nutritious and functional food products such as vegetable beverages. However, in order to use chickpea to develop a functional, healthy and nutritional beverage, its processing is needed to improve the digestibility and increase the quantity of soluble components into an aqueous system. Therefore, in the present research work, extrusion of whole chickpea and sequential hydrolyses with Alcalase® and α-amylase were evaluated to develop a high soluble chickpea-based food ingredient. The thermoplastic extrusion process was carried out varying processing moisture (15.6% or 22.55%), final barrel temperature (143 °C or 150 °C) and screw speed (450 rpm, 580

rpm, or 700 rpm) to generate three SME inputs (127.95 Wh/kg, 161.58 Wh/kg, and 199.13 Wh/kg). After extrusion, flours were hydrolyzed with Alcalase® and α-amylase in order to maximize soluble compounds after hydration. In general, extrusion did not affect chemical composition, but caused structural modifications that influenced changes in functional properties and modified in vitro protein and starch digestibilities. Extruded chickpea flours presented higher content of soluble proteins and increased starch hydrolysis after Alcalase® and α-amylase treatment, respectively. It was found that extrusion treatment of chickpea with a SME input of 127.95 Wh/kg produced at 22.5% processing moisture, 150 °C of final temperature and 580 rpm of screw speed in

combination with the later Alcalase®/α-amylase treatments achieved the highest release of both soluble proteins (70%) and soluble solids (62%) and the highest degree of starch hydrolysis (84%). These results were used to transform whole chickpea flour into a valuable soluble food ingredient by means of a combination of extrusion and sequential Alcalase®/α-amylase treatment. This soluble food ingredient was freeze dried, milled and characterized in terms of chemical composition and protein quality. It was found that the resulting powder had 53.7%, 20.2% and 3.6% of reducing sugars, proteins, and fat contents, respectively. The soluble powder had an in vitro protein digestibility of 83.1%, a PDCAAS value of 0.831 and it did not present any limiting amino acids which suggest that this product had the potential to be used to develop instant chickpea beverages with an excellent nutrimental quality.

Maestro en Ciencias con especialidad en Biotecnología

Master thesis

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS NUTRIENTES

Nutrición química y orgánica en aguacate Hass en Filo de Caballos, Guerrero, México.

AGUSTIN DAMIAN NAVA VICTOR ARTURO GONZALEZ HERNANDEZ OSCAR TALAVERA MENDOZA ELIAS HERNANDEZ CASTRO FRANCISCO PALEMON ALBERTO HECTOR SOTELO NAVA (2015)

The study was conducted in the village of Filo de Caballos, municipality of Leonardo Bravo, Guerrero, Mexico, from November 2011 to October 2012, in an orchard of Hass avocado, 5 years old. The objective was to evaluate the treatment of chemical and organic nutrition of avocado trees; fertilizers used were: 50 kg tree of cattle dung (manure); 200-100-200 kg ha-1 of N-P-K (edaphic) and 30-10-15.30 kg ha-1 of Ca-Mg-B (foliar). We found that in buds, treatment manure + edaphic + foliar (41 shoots/branch) was better than treatments manure + edaphic (19 shoots/branch), leaf (9 shoots/branch) and the control (21 shoots/branch). And with 17 fruits, manure + treatment + foliar edaphic significantly exceeded the edaphic + foliar treatments (6 fruits), leaf (1 fruit) and the control (3 fruits). The manure + foliar treatment had the highest length (16 cm) of the main shoot, beating the treatment of manure + edaphic (7 cm) and leaf (9 cm). The edaphic + foliar treatment (75 cm2 ) had higher leaf area than control (65 cm2 ) and had the highest fruit weight 2.62 kg with 10 fruits, which was significantly higher than the control (1.51 kg 10 fruits).

Article

Avocado Nutrients vegetative and reproductive growth CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS OTRAS ESPECIALIDADES AGRARIAS

Extracts from six native plants of the Yucatan Peninsula hinder mycelial growth of Fusarium equiseti and F. oxysporum, pathogens of Capsicum chinense

PATRICIA CRUZ CERINO Jairo Cristóbal Alejo VIOLETA RUIZ CARRERA GERMAN CARNEVALI FERNANDEZ CONCHA BLANCA MARINA VERA KU Jesús Martin Fernando Reyes MARIA MARCELA GAMBOA ANGULO (2020)

Fusarium equiseti strain FCHE and Fusarium oxysporum strain FCHJ were isolated from the roots of wilting habanero pepper (Capsicum chinense Jacq.) seedlings with root rot. Toward developing a biorational control of these serious phytopathogenic strains, ethanolic (EE) and aqueous (AE) extracts of different vegetative parts of 40 tropical native plants of the Yucatán Peninsula were screened for antifungal activity. Extracts of six out of 40 assayed plants were effective, and the most inhibitory extracts were studied further. EEs from Mosannona depressa (bark from stems and roots), Parathesis cubana (roots), and Piper neesianum (leaves) inhibited mycelial growth of both strains. Each active EE was then partitioned between hexane and acetonitrile. The acetonitrile fraction from M. depressa stem bark (MDT-b) had the lowest minimum inhibitory concentration of 1000 µg/mL against both pathogens and moderate inhibitory concentration (IC50) of 462 against F. equiseti and 472 µg/mL against F. oxysporum. After 96 h treatment with EE from M. depressa stem bark, both strains had distorted hyphae and conidia and collapsed conidia in scanning electron micrographs. Liquid chromatography–ultraviolet–high resolution mass spectrometry analysis revealed that the major component of the fraction was α-asarone. Its antifungal effect was verified using a commercial standard, which had an IC50 of 236 µg/mL against F. equiseti and >500 µg/mL against F. oxysporum. Furthermore, the P. cubana hexane fraction and P. neesianum acetonitrile fraction had antifungal activity against both Fusarium pathogens. These compounds provide new options for biorational products to control phytopathogenic fungi.

Article

ANTIFUNGAL Α-ASARONE HABANERO PEPPER PHYTOPATHOGENS MOSANNONA DEPRESSA PLANT EXTRACTS BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA MOLECULAR BIOLOGÍA MOLECULAR DE PLANTAS BIOLOGÍA MOLECULAR DE PLANTAS

Sustainability in teaching: an evaluation of university teachers and students

Rosa María Brito Carmona Columba Rodríguez Alviso Jose Luis Aparicio Lopez (2018)

Since the 1970s, interest in caring for the environment has gained traction and the environmental education movement has gained momentum. The Talloires Declaration was the first document to incorporate sustainable development into higher education. After that, higher education institutions assumed the social responsibility of training human resources with a sustainable vision

Article

Sustainability Teaching Evaluation Higher education CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO

Submm/mm Galaxy Counterpart Identification Using a Characteristic Density Distribution

Itziar Aretxaga David Hughes (2013)

We present a new submm/mm galaxy counterpart identification technique whichbuilds on the use of Spitzer IRAC colors as discriminators between likely counter-parts and the general IRAC galaxy population. Using 102 radio- and SMA-confirmedcounterparts to AzTEC sources across three fields (GOODS-N, GOODS-S, and COSMOS), we develop a non-parametric IRAC color-color characteristic density distribution (CDD), which, when combined with positional uncertainty information vialikelihood ratios, allows us to rank all potential IRAC counterparts around SMGsand calculate the significance of each ranking via the reliability factor. We reportall robust and tentative radio counterparts to SMGs, the first such list available forAzTEC/COSMOS, as well as the highest ranked IRAC counterparts for all AzTECSMGs in these fields as determined by our technique. We demonstrate that the technique is free of radio bias and thus applicable regardless of radio detections. For observations made with a moderate beamsize (∼18′′), this technique identifies ∼85 percent of SMG counterparts. For much larger beamsizes (≳30′′), we report identificationrates of 33-49 per cent. Using simulations, we demonstrate that this technique is animprovement over using positional information alone for observations with facilities such as AzTEC on the LMT and SCUBA-2 on JCMT.

Article

Submillimetre: galaxies Radio continuum: galaxies Infrared: galaxies Galaxies: high redshift Techniques: photometric Methods: data analysis CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA ASTRONOMÍA Y ASTROFÍSICA RADIOASTRONOMÍA RADIOASTRONOMÍA

X-ray detections of submillimetre galaxies: active galactic nuclei versus starburst contribution

Itziar Aretxaga David Hughes (2013)

We present a large-scale study of the X-ray properties and near-IR-to-radio spectral energy distributions (SEDs) of submillimetre galaxies (SMGs) detected at 1.1 mm with the AzTEC instrument across a ∼1.2 square degree area of the sky. Combining deep 2–4 Ms Chandra data with Spitzer IRAC/MIPS and Very Large Array data within the Great Observatories Origins Deep Survey North (GOODS-N), GOODS-S and COSMOS fields, we find evidence for active galactic nucleus (AGN) activity in ∼14 per cent of 271 AzTEC SMGs, ∼28 per cent considering only the two GOODS fields. Through X-ray spectral modelling and multiwavelength SED fitting using Monte Carlo Markov chain techniques to Siebenmorgen et al. (AGN) and Efstathiou, Rowan-Robinson & Siebenmorgen (starburst) templates, we find that while star formation dominates the IR emission, with star formation rates (SFRs) ∼100–1000M⊙ yr⁻¹, the X-ray emission for most sources is almost exclusively from obscured AGNs, with column densities in excess of 10²³ cm⁻². Only for ∼6 per cent of our sources do we find an X-ray-derived SFR consistent with NIR-to-radio SED derived SFRs. Inclusion of the X-ray luminosities as a prior to the NIR-to-radio SED effectively sets the AGN luminosity and SFR, preventing significant contribution from the AGN template. Our SED modelling further shows that the AGN and starburst templates typically lack the required 1.1 mm emission necessary to match observations, arguing for an extended, cool dust component. The cross-correlation function between the full samples of X-ray sources and SMGs in these fields does not indicate a strong correlation between the two populations at large scales, suggesting that SMGs and AGNs do not necessarily trace the same underlying large-scale structure. Combined with the remaining X-ray-dim SMGs, this suggests that sub-mm-bright sources may evolve along multiple tracks, with X-ray-detected SMGs representing transitionary objects between periods of high star formation and AGN activity, while X-ray-faint SMGs represent a brief starburst phase of more normal galaxies.

Article

Galaxies: active Galaxies: high-redshift Galaxies: starburst Submillimetre: galaxies X-rays: galaxies CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA ASTRONOMÍA Y ASTROFÍSICA ASTRONOMÍA Y ASTROFÍSICA