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16
result(s) for
"Esquivel-Hernández, Diego"
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Effect of metformin and metformin/linagliptin on gut microbiota in patients with prediabetes
by
Mendoza-Ortíz, Cristian
,
Resendis-Antonio, Osbaldo
,
Girón-Villalobos, David
in
631/553
,
692/163
,
Adult
2024
Lifestyle modifications, metformin, and linagliptin reduce the incidence of type 2 diabetes (T2D) in people with prediabetes. The gut microbiota (GM) may enhance such interventions' efficacy. We determined the effect of linagliptin/metformin (LM) vs metformin (M) on GM composition and its relationship to insulin sensitivity (IS) and pancreatic β-cell function (Pβf) in patients with prediabetes. A cross-sectional study was conducted at different times: basal, six, and twelve months in 167 Mexican adults with prediabetes. These treatments increased the abundance of GM SCFA-producing bacteria M (
Fusicatenibacter
and
Blautia
) and LM (
Roseburia
,
Bifidobacterium,
and [
Eubacterium
]
hallii group
). We performed a mediation analysis with structural equation models (SEM). In conclusion, M and LM therapies improve insulin sensitivity and Pβf in prediabetics. GM is partially associated with these improvements since the SEM models suggest a weak association between specific bacterial genera and improvements in IS and Pβf.
Journal Article
Supercritical Carbon Dioxide and Microwave-Assisted Extraction of Functional Lipophilic Compounds from Arthrospira platensis
by
Cuéllar-Bermúdez, Sara
,
Esquivel-Hernández, Diego
,
Rostro-Alanis, Magdalena
in
alpha-Linolenic Acid - analysis
,
alpha-Tocopherol - analysis
,
Arthrospira platensis
2016
Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE) and microwave-assisted extraction (MAE). The temperature (T) factor was evaluated for MAE, while for SFE, pressure (P), temperature (T), and co-solvent (ethanol) (CS) were evaluated. The maximum extraction yield of the obtained oleoresin was (4.07% ± 0.14%) and (4.27% ± 0.10%) for SFE and MAE, respectively. Extracts were characterized by gas chromatography mass spectrometry (GC-MS) and gas chromatography flame ionization detector (GC-FID). The maximum contents of functional lipophilic compounds in the SFE and MAE extracts were: for carotenoids 283 ± 0.10 μg/g and 629 ± 0.13 μg/g, respectively; for tocopherols 5.01 ± 0.05 μg/g and 2.46 ± 0.09 μg/g, respectively; and for fatty acids 34.76 ± 0.08 mg/g and 15.88 ± 0.06 mg/g, respectively. In conclusion, the SFE process at P 450 bar, T 60 °C and CS 53.33% of CO2 produced the highest yield of tocopherols, carotenoids and fatty acids. The MAE process at 400 W and 50 °C gives the best extracts in terms of tocopherols and carotenoids. For yield and fatty acids, the MAE process at 400 W and 70 °C produced the highest values. Both SFE and MAE showed to be suitable green extraction technologies for obtaining functional lipophilic compounds from Arthrospira platensis.
Journal Article
Multi-product biorefinery from Arthrospira platensis biomass as feedstock for bioethanol and lactic acid production
by
Esquivel-Hernández, Diego A.
,
de Souza Vandenberghe, Luciana Porto
,
Torres-Acosta, Mario A.
in
631/326
,
631/61
,
Acid production
2021
With the aim to reach the maximum recovery of bulk and specialty bioproducts while minimizing waste generation, a multi-product biorefinery for ethanol and lactic acid production from the biomass of cyanobacterium
Arthrospira platensis
was investigated. Therefore, the residual biomass resulting from different pretreatments consisting of supercritical fluid extraction (SF) and microwave assisted extraction with non-polar (MN) and polar solvents (MP), previously applied on
A. platensis
to extract bioactive metabolites, was further valorized. In particular, it was used as a substrate for fermentation with
Saccharomyces cerevisiae
LPB-287 and
Lactobacillus acidophilus
ATCC 43121 to produce bioethanol (BE) and lactic acid (LA), respectively. The maximum concentrations achieved were 3.02 ± 0.07 g/L of BE by the MN process at 120 rpm 30 °C, and 9.67 ± 0.05 g/L of LA by the SF process at 120 rpm 37 °C. An economic analysis of BE and LA production was carried out to elucidate the impact of fermentation scale, fermenter costs, production titer, fermentation time and cyanobacterial biomass production cost. The results indicated that the critical variables are fermenter scale, equipment cost, and product titer; time process was analyzed but was not critical. As scale increased, costs tended to stabilize, but also more product was generated, which causes production costs per unit of product to sharply decrease. The median value of production cost was US$ 1.27 and US$ 0.39, for BE and LA, respectively, supporting the concept of cyanobacterium biomass being used for fermentation and subsequent extraction to obtain ethanol and lactic acid as end products from
A. platensis
.
Journal Article
Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis
by
Chen, Wei
,
Cuéllar-Bermúdez, Sara
,
Ontiveros-Valencia, Aura
in
alpha-Tocopherol - chemistry
,
alpha-Tocopherol - pharmacology
,
Anti-Infective Agents - chemistry
2017
Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO2). Pressure (P), temperature (T), co-solvent (CX), static extraction (SX), dispersant (Di) and dynamic extraction (DX) were evaluated as process parameters through a Plackett–Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of β-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin–Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05). Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g.
Journal Article
Diffusion on PCA-UMAP Manifold: The Impact of Data Structure Preservation to Denoise High-Dimensional Single-Cell RNA Sequencing Data
by
Osbaldo, Resendis-Antonio
,
Daniel, Neri-Rosario
,
David, Giron-Villalobos
in
Approximation
,
cell structures
,
data collection
2024
Single-cell transcriptomics (scRNA-seq) is revolutionizing biological research, yet it faces challenges such as inefficient transcript capture and noise. To address these challenges, methods like neighbor averaging or graph diffusion are used. These methods often rely on k-nearest neighbor graphs from low-dimensional manifolds. However, scRNA-seq data suffer from the ‘curse of dimensionality’, leading to the over-smoothing of data when using imputation methods. To overcome this, sc-PHENIX employs a PCA-UMAP diffusion method, which enhances the preservation of data structures and allows for a refined use of PCA dimensions and diffusion parameters (e.g., k-nearest neighbors, exponentiation of the Markov matrix) to minimize noise introduction. This approach enables a more accurate construction of the exponentiated Markov matrix (cell neighborhood graph), surpassing methods like MAGIC. sc-PHENIX significantly mitigates over-smoothing, as validated through various scRNA-seq datasets, demonstrating improved cell phenotype representation. Applied to a multicellular tumor spheroid dataset, sc-PHENIX identified known extreme phenotype states, showcasing its effectiveness. sc-PHENIX is open-source and available for use and modification.
Journal Article
Rapid Lipid Content Screening in Neochloris oleoabundans Utilizing Carbon-Based Dielectrophoresis
by
Camacho-León, Sergio
,
Esquivel-Hernández, Diego
,
Martínez-Chapa, Sergio
in
Algae
,
biofuel
,
Biomass
2021
In this study, we carried out a heterogeneous cytoplasmic lipid content screening of Neochloris oleoabundans microalgae by dielectrophoresis (DEP), using castellated glassy carbon microelectrodes in a PDMS microchannel. For this purpose, microalgae were cultured in nitrogen-replete (N+) and nitrogen-deplete (N−) suspensions to promote low and high cytoplasmic lipid production in cells, respectively. Experiments were carried out over a wide frequency window (100 kHz–30 MHz) at a fixed amplitude of 7 VPP. The results showed a statistically significant difference between the dielectrophoretic behavior of N+ and N− cells at low frequencies (100–800 kHz), whereas a weak response was observed for mid- and high frequencies (1–30 MHz). Additionally, a finite element analysis using a 3D model was conducted to determine the dielectrophoretic trapping zones across the electrode gaps. These results suggest that low-cost glassy carbon is a reliable material for microalgae classification—between low and high cytoplasmic lipid content—through DEP, providing a fast and straightforward mechanism.
Journal Article
Diversity of an uncommon elastic hypersaline microbial mat along a small-scale transect
by
Cifuentes Camargo, Julián Felipe
,
Figueroa, Mario
,
Esquivel-Hernandez, Diego A.
in
Analysis
,
Biodiversity
,
Biogeography
2022
We evaluated the microbial diversity and metabolome profile of an uncommon hypersaline elastic microbial mat from Cuatro Ciénegas Basin (CCB) in the Chihuahuan Desert of Coahuila, México. We collected ten samples on a small scale transect (1.5-m) and described its microbial diversity through NGS-based ITS and 16S rDNA gene sequencing. A very low number of taxa comprised a considerable proportion of the mat and were shared across all sampling points, whereas the rare biosphere was more phylogenetically diverse (Faith’s Phylogenetic Diversity (FPD) index) and phylogenetically disperse (using a null model distribution of Phylogenetic Species Clustering (nmdPSC)) than the abundant (high read count) taxa for both analyzed libraries. We also found a distinctive metabolome profile for each sample and were able to tentatively annotate several classes of compounds with relevant biological properties.
Journal Article
Using high hydrostatic pressures to retain the antioxidant compounds and to reduce the enzymatic activity of a pitaya–pineapple (Stenocereus sp.–Fragaria ananassa) beverage
by
Escobedo-Avellaneda, Zamantha
,
Esquivel-Hernandez, Diego A.
,
Parra-Saldívar, Roberto
in
antioxidant activity
,
Antioxidants
,
ascorbic acid
2017
Pitaya (
Stenocereus
sp.) is a fruit native to arid and semiarid areas of Mexico. It has high antioxidant activity mainly due to its contents of betalains and phenolics, but its consumption is limited due to very short shelf-life and not very recognized flavor. A beverage of pitaya and pineapple was formulated to improve sensory properties. A high hydrostatic pressure (HHP) study at 400–600 MPa and 25 °C for 2–10 min was applied in the beverage and the effect on the contents of vitamin C, total phenolics and betalains, and the pectin methylesterase (PME) activity of pitaya–pineapple beverages, was evaluated. The effect of the come up time (CUT) was also studied. Vitamin C contents increased from 5% at 600 MPa-CUT to 64% at 400 MPa/CUT. Total phenolic concentrations decreased (20–48%) at all processing conditions tested at 400 MPa/CUT, total betacyanins were retained. At 500 MPa/10 min losses of betaxanthins of up to 6% occurred. The maximum PME activity decrease was 23% at 600 MPa 5 min, but an increase of PME activity 7% was observed at 400 MPa/10 min. HHP seem to be a good option to retain most of the antioxidant compounds in pitaya–pineapple beverage, but more studies are necessary to inactivate PME.
Journal Article
Integrated biorefinery from Arthrospira platensis biomass as feedstock for bioethanol and lactic acid production
by
Esquivel-Hernandez, Diego A
,
Parra-Saldivar, Roberto
,
Pennacchio, Anna
in
Acid production
,
Acids
,
Arthrospira platensis
2019
An integrated biorefinery for ethanol and lactic acid production from the biomass of cyanobacterium Arthrospira platensis was investigated. Different pretreatments consisting of supercritical fluid extraction (SFE) and microwave assisted extraction (MAE) with non-polar (MAE-NPS) and polar solvents (MAE-PS) were tested on cyanobacterial biomass to obtain bioactive metabolites and the resulting residual biomass was used as a substrate for fermentation with Saccharomyces cerevisiae LPB-287 and Lactobacillus acidophilus ATCC 43121 to produce ethanol and lactic acid, respectively. The maximum concentrations achieved in our processes were 3.02±0.07 g/L of ethanol by the MAE-NPS process at 120 rpm 30 °C, and 9.67±0.05 g/L of lactic acid by the SFE process at 120 rpm 37 °C. Our results suggest that the proposed approach can be successfully applied in bioactive metabolites extraction and subsequently in the production of Ethanol and Lactic acid from A. platensis depleted biomass.