Juan Manuel Alvarez-Caballero

Dr. Juan Manuel Alvarez-Caballero

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Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 June 2021 in Polymers
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CMCarlos Molina-Ramírez
Carlos Molina-Ramírez
PMPaulina Mazo Mazo Márquez
Paulina Mazo Mazo Márquez
Robin Zuluaga GallegoRobin Zuluaga Gallego
Robin Zuluaga Gallego
Piedad Felisinda GañánPiedad Felisinda Gañán
Piedad Felisinda Gañán
JAJuan Manuel Alvarez-Caballero
Juan Manuel Alvarez-Caballero
Scales of Prochilodus magdalenae, a Colombian endemic fish species, were used to obtain chitosan for application as an antibacterial agent integrated into starch-based films. Analysis of its composition during the demineralization and deproteinization process indicated that minerals and protein were both removed successfully. At this point, mild conditions for the deacetylation process were employed, namely, 2, 4, and 6 wt.% NaOH at room temperature for 16 h. Chitosan processed under 2 wt.% NaOH had low molecular weight, with the lowest value of 107.18 ± 24.99 kDa, which was closely related to its antibacterial activity. Finally, this chitosan was integrated into a banana starch-based film, and its antibacterial activity was assayed in Escherichia coli and Staphylococcus aureus cultures, with positive results in the former culture, especially due to the low-molecular-weight characteristic of chitosan.

23 December 2011 in Journal of Cross-Cultural Psychology
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ACA. Timothy Church
A. Timothy Church
SWStephanie L. Willmore
Stephanie L. Willmore
AAAdisa T. Anderson
Adisa T. Anderson
MOMasayuki Ochiai
Masayuki Ochiai
NPNoriko Porter
Noriko Porter
FOFernando A. Ortiz
Fernando A. Ortiz
Cultural differences in implicit theories and self-perceptions of traitedness were examined in the United States (N = 198), Mexico (N = 257), the Philippines (N = 212), and Japan (N = 225). Participants in all four cultures endorsed beliefs about the longitudinal stability, cross-situational consistency, and predictive validity of traits. At the same time, Americans and Mexicans, more than Filipinos and Japanese, endorsed implicit trait or dispositionist perspectives and described their own behavior as traited or consistent (i.e., lower in self-monitoring). Alternative measurement formats were compared and led to the conclusion that forced-choice measures may be advantageous in some cases, particularly when acquiescence bias may impact cross-cultural comparisons. Cultural differences were observed in participants’ perceptions of the individualism-collectivism, dialecticism, and tightness-looseness of their respective cultures and these measures partially mediated some of the cultural differences in traitedness. Overall, the results supported an integration of trait and cultural psychology perspectives, leading to a more comprehensive understanding of the relationship between culture and personality.

16 November 2020 in Processes
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CMCarlos Molina-Ramírez
Carlos Molina-Ramírez
JAJuan Manuel Alvarez-Caballero
Juan Manuel Alvarez-Caballero
Robin Zuluaga GallegoRobin Zuluaga Gallego
Robin Zuluaga Gallego
CCCristina Castro
Cristina Castro
Piedad Felisinda GañánPiedad Felisinda Gañán
Piedad Felisinda Gañán
Currently, cellulose nanostructures are among the most promising structures, and extensive work in materials and biotechnology industries is aimed at identifying an efficient process of production. Even when production at the laboratory scale is successful, crucial aspects of increased commercial applications for cellulose nanostructures are linked to large-scale production. Large-scale production requires a balance between the cost of the culture medium and product value. Therefore, in this work, for the optimization and scaling up of bacterial nanocellulose, a culture medium consisting of rotten banana unsuitable for human consumption was used for the first time as an inexpensive feedstock. Initially, the bacterial nanocellulose (BNC) culture medium conditions were optimized, and it was established that a glucose concentration of 26.4 g/L and a V/A ratio of 2.2 cm were the optimal conditions for production reaching a BNC yield of 5 g/L, which was 42.4% higher than the best result initially obtained. Finally, the scale-up process was performed, implementing a regime analysis methodology by comparing the characteristic times of the critical mechanisms involved in BNC production, namely, microbial growth, glucose consumption, BNC production, and glucose diffusion into the BNC membrane, as the first approach for this type of BNC production process. The mechanism underlying the BNC production process is glucose diffusion into the BNC membrane (characteristic time, 675.47 h). Thus, the V/A ratio was selected as the scale-up criterion most suitable for producing BNC under static culture conditions, allowing the production of 16 g of BNC after 12 d of fermentation in a plastic bioreactor, which was 3378% higher than that produced in glass vessels. The results obtained in this study may initiate further improvements in BNC commercial production by exploiting different feedstocks.

29 November 2019 in Plants
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JAJuan Manuel Alvarez-Caballero
Juan Manuel Alvarez-Caballero
Ericsson Coy-BarreraEricsson Coy-Barrera
Ericsson Coy-Barrera
Plant materials (i.e., leaves, fruits, and seeds) from 40 trees of Azadirachta indica A. Juss. were collected from six different locations across the Colombian Caribbean coast. Eighty-four ethanolic extracts were prepared and the total limonoid contents (TLiC) and the antifungal activity against Fusarium oxysporum conidia were measured. Their chemical profiles were also recorded via liquid chromatography-electrospray ionization interface-mass spectrometry (LC-ESI-MS) analysis and the top-ranked features were then annotated after supervised multivariate statistics. Inter-location chemical variability within sample set was assessed by sparse partial least squares discriminant analysis (sPLS-DA) and the chemical profiles and biological activity datasets were integrated through single-Y orthogonal partial least squares (OPLS) to identify antifungal bioactives in test extracts. The TLiC and antifungal activity (IC50 values) of the A. indica-derived extracts were found to be ranging from 4.5 to 48.5 mg limonin equivalent per g dry extract and 0.08–44.8 μg/mL, respectively. The presence/abundance of particular limonoids between collected samples influenced the variability among locations. In addition, the integration of chemical and antifungal activity datasets showed five features as markers probably contributing to the bioactivity, annotated as compounds with an azadirone-like moiety. To validate the information provided by the single-Y OPLS model, a high performance liquid chromatography (HPLC)-based microfractionation was then carried out on an active extract. The combined plot of chromatographic profile and microfraction bioactivity also evidenced five signals possessing the highest antifungal activity. The most active limonoid was identified as nimonol 1. Hence, this untargeted metabolite profiling was considered as a convenient tool for identifying metabolites as inter-location markers as well as antifungals against Fusarium oxysporum.

8 October 2019 in Biomolecules
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JAJuan Manuel Alvarez-Caballero
Juan Manuel Alvarez-Caballero
ECEricsson Coy-Barrera
Ericsson Coy-Barrera
Ericsson Coy-BarreraEricsson Coy-Barrera
Ericsson Coy-Barrera
Bio-guided fractionation performed on the leaves-derived ethanol extract of Esenbeckia alata (Rutaceae), a plant used in traditional medicine, led to the isolation of two alkaloids, kokusaginine 1 and flindersiamine 2, as main cytotoxic agents. Primary ethanolic extract and raw fractions exhibited cell inhibition against five cancer cell lines at different levels (25–97% inhibition at 50 µg/mL) as well as isolated alkaloids 1–2 (30–90% inhibition at 20 µM). Although alkaloid 2 generally was the most active compound, both alkaloids showed a selective effect on K562, a human chronic myelogenous leukemia cell line. The E1-like ubiquitin-activating enzymes (e.g., UBA5) have been recently described as important targets for future treatment of cancer progression, such as leukemia, among others. Therefore, as a rationale to the observed cytotoxic selectivity, an in-silico evaluation by molecular docking and molecular dynamics was also explored. Compounds 1–2 exhibited good performance on the interaction within the active site of UBA5.

3 February 2026 in Pharmaceutics
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BÜBurak ÜNLÜ
Burak ÜNLÜ
JRJosé Ropero
José Ropero
JAJuan Manuel Alvarez-Caballero
Juan Manuel Alvarez-Caballero
J.M Flórez-CastilloJ.M Flórez-Castillo
J.M Flórez-Castillo
STSerbülent Türk
Serbülent Türk
Smart hydrogels, which combine hydrogel properties such as biocompatibility, high drug loading capacity, and injectability while being responsive to external stimuli, are a subclass of smart materials. Smart hydrogels respond to effects that are not harmful to the human body, such as temperature, pH, light, and biomolecules. Furthermore, some smart hydrogels possess dual-responsive properties or can be multifunctional, exhibiting both adhesive and responsive behavior to external stimuli. Smart hydrogels have made groundbreaking advances in the field of biomedical. They have been improved through structural modifications and by gaining the ability to be multi-responsive. Controlling drug release and biofilm disruption by using these smart hydrogels is one of the efficient strategies to reduce antimicrobial resistance and the number of deaths caused by microbial diseases. In this review, the preparation of smart hydrogels, their various types and applications in the treatment of microbial diseases were investigated.