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"Flores, Ignacio"
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Experimental investigation on the physical, microstructural, and mechanical properties of hemp limecrete
by
Chávez-Delgado, Manuel
,
Marzialetti B, Teresita
,
Avudaiappan, Siva
in
639/166/986
,
639/301/1023/303
,
Green buildings
2023
This paper investigates the hemp limecrete mechanical and microstructural performance of a new sustainable and environmental friendly building material. Several studies have investigated the hemp limecrete focusing on the non-structural applications. The newly developed hemp limecrete consists of high mechanical and microstructural properties. The specimens were prepared with varying lengths and proportions of hemp fibers with lime and tested for compressive strength, flexural strength, thermal conductivity and microstructural analysis like SEM and EDS. The study found that the optimal fiber content for making mortars was between 2 and 4%. This conclusion was reached after analyzing the influence of fiber length and ratio on the properties of the mortars. The dry unit weight decreased when the fiber content was higher than 4%. In terms of strength, the study found that the flexural strength of the hemp limecrete improved with an increase in fiber ratio, but the compressive strength decreased. However, with 2% hemp fiber, compressive strengths of 3.48 MPa and above were obtained. The study also highlighted the good thermal insulation properties and dimensional stability of hemp limecrete. These findings have important implications for the use of hemp limecrete as a sustainable building material. The results suggest that hemp limecrete has the potential to be a viable alternative to conventional concrete in specific applications, particularly in areas where environmental sustainability is a priority.
Journal Article
NLRP3 inflammasome suppression improves longevity and prevents cardiac aging in male mice
by
Marín‐Aguilar, Fabiola
,
Bullón, Pedro
,
Alcocer‐Gómez, Elísabet
in
1-Phosphatidylinositol 3-kinase
,
Adiponectin
,
Aging
2020
While NLRP3‐inflammasome has been implicated in cardiovascular diseases, its role in physiological cardiac aging is largely unknown. During aging, many alterations occur in the organism, which are associated with progressive impairment of metabolic pathways related to insulin resistance, autophagy dysfunction, and inflammation. Here, we investigated the molecular mechanisms through which NLRP3 inhibition may attenuate cardiac aging. Ablation of NLRP3‐inflammasome protected mice from age‐related increased insulin sensitivity, reduced IGF‐1 and leptin/adiponectin ratio levels, and reduced cardiac damage with protection of the prolongation of the age‐dependent PR interval, which is associated with atrial fibrillation by cardiovascular aging and reduced telomere shortening. Furthermore, old NLRP3 KO mice showed an inhibition of the PI3K/AKT/mTOR pathway and autophagy improvement, compared with old wild mice and preserved Nampt‐mediated NAD+ levels with increased SIRT1 protein expression. These findings suggest that suppression of NLRP3 prevented many age‐associated changes in the heart, preserved cardiac function of aged mice and increased lifespan. In this study, we have shown the potential role of the NLRP3 inhibition to modulate several anti‐aging mechanisms during cardiac aging. This work highlights the importance of examining the therapeutic and prophylatic value of small molecule inhibitors of NLRP3 and its effects as potential therapy for preventing cardiac and metabolic aging.
Journal Article
The ALT pathway generates telomere fusions that can be detected in the blood of cancer patients
by
Rodriguez, Manuel José Gómez
,
Cortés-Ciriano, Isidro
,
Cascão, Rita
in
45/23
,
631/67/2322
,
631/67/69
2024
Telomere fusions (TFs) can trigger the accumulation of oncogenic alterations leading to malignant transformation and drug resistance. Despite their relevance in tumour evolution, our understanding of the patterns and consequences of TFs in human cancers remains limited. Here, we characterize the rates and spectrum of somatic TFs across >30 cancer types using whole-genome sequencing data. TFs are pervasive in human tumours with rates varying markedly across and within cancer types. In addition to end-to-end fusions, we find patterns of TFs that we mechanistically link to the activity of the alternative lengthening of telomeres (ALT) pathway. We show that TFs can be detected in the blood of cancer patients, which enables cancer detection with high specificity and sensitivity even for early-stage tumours and cancers of high unmet clinical need. Overall, we report a genomic footprint that enables characterization of the telomere maintenance mechanism of tumours and liquid biopsy analysis.
Telomere fusions are linked to oncogenesis in multiple cancer types, but their patterns are poorly understood. Here, the authors use whole-genome sequencing data to compare fusion events across cancer types, and identify a novel type of telomere fusion pattern associated with the Alternative Lengthening of Telomeres (ALT) pathway that can be used for liquid biopsy analysis.
Journal Article
Nutrient Uptake of Two Semidomesticated Jaltomata Schltdl. Species for Their Cultivation
by
Sandoval-Villa, Manuel
,
Flores-Sánchez, Ignacio Darío
,
Uscanga-Mortera, Ebandro
in
absorption curves
,
Accumulation
,
Carbohydrates
2025
The nutrient uptake of a species under cultivated conditions is important for program fertilization. The Jaltomata genus has two semidomesticated species, J. procumbens and J. tlaxcala, used as food and considered with potential for their study in controlled environments. The objective of this research was to determine nutrient uptake curves of these species in a greenhouse and using hydroponics. The research was carried out at the Colegio de Postgraduados, Campus Montecillo, Texcoco, State of Mexico, from August to November 2020. The treatments included the following: two species and three electrical conductivity levels: 1, 2, and 3 dS m−1. Nutrients in leaf and total dry matter (TDM) were determined. Variability between species and phenological stages on the nutrient concentration and accumulation of TDM was observed. For macronutrients, J. procumbens concentrated in descending order more P from the vegetative stage (4.21–2.43 g kg−1 dry matter), and Mg until fructification (4.92–3.26 g kg−1 dry matter), for K it was higher at vegetative (52.29 g kg−1 dry matter) and harvesting stages (26.05 g kg−1 dry matter), and N (23.92 g kg−1 dry matter) at flowering; J. tlaxcala concentrated more Ca from fructification (10.10–13.85 g kg−1 dry matter). For micronutrients, J. tlaxcala concentrated more Fe from the vegetative stage (157.7–207.5 mg kg−1 dry matter), B and Zn at 23.3–38.4 and 26.04–28.45 mg kg−1 dry matter, respectively, from flowering, and Mn (108.4–232.28 mg kg−1 dry matter) from fructification. The main structures of TDM accumulation by vegetative stage in J. procumbens were the leaf and root (vegetative and flowering), root and stem (fructification), and reproductive structures and root (harvesting); in J. tlaxcala, the main structures were the leaf and root (vegetative), root and leaf (flowering and fructification), and root and reproductive structures (harvesting). Due to this variability, specific fertilization programs are required for each species.
Journal Article
Effects of Telomerase and Telomere Length on Epidermal Stem Cell Behavior
2005
A key process in organ homeostasis is the mobilization of stem cells out of their niches. We show through analysis of mouse models that telomere length, as well as the catalytic component of telomerase, Tert, are critical determinants in the mobilization of epidermal stem cells. Telomere shortening inhibited mobilization of stem cells out of their niche, impaired hair growth, and resulted in suppression of stem cell proliferative capacity in vitro. In contrast, Tert overexpression in the absence of changes in telomere length promoted stem cell mobilization, hair growth, and stem cell proliferation in vitro. The effects of telomeres and telomerase on stem cell biology anticipate their role in cancer and aging.
Journal Article
A p53-Dependent Response Limits Epidermal Stem Cell Functionality and Organismal Size in Mice with Short Telomeres
2009
Telomere maintenance is essential to ensure proper size and function of organs with a high turnover. In particular, a dwarf phenotype as well as phenotypes associated to premature loss of tissue regeneration, including the skin (hair loss, hair graying, decreased wound healing), are found in mice deficient for telomerase, the enzyme responsible for maintaining telomere length. Coincidental with the appearance of these phenotypes, p53 is found activated in several tissues from these mice, where is thought to trigger cellular senescence and/or apoptotic responses. Here, we show that p53 abrogation rescues both the small size phenotype and restitutes the functionality of epidermal stem cells (ESC) of telomerase-deficient mice with dysfunctional telomeres. In particular, p53 ablation restores hair growth, skin renewal and wound healing responses upon mitogenic induction, as well as rescues ESCmobilization defects in vivo and defective ESC clonogenic activity in vitro. This recovery of ESC functions is accompanied by a downregulation of senescence markers and an increased proliferation in the skin and kidney of telomerase-deficient mice with critically short telomeres without changes in apoptosis rates. Together, these findings indicate the existence of a p53-dependent senescence response acting on stem/progenitor cells with dysfunctional telomeres that is actively limiting their contribution to tissue regeneration, thereby impinging on tissue fitness.
Journal Article
The capital share and income inequality: Increasing gaps between micro and macro-data
2021
In this paper, I study how the contrasting coverage of labour and capital incomes affects inequality estimates. I use national accounts as a benchmark to evaluate the scope of household surveys, for a number of countries, and tax data for the United States. Due to both measurement error and conceptual differences, capital income is always more underestimated. In most countries, the gap grows during the last two decades. Based on accounting identities, I show that inequality estimates are likely affected in level, trend and composition. Surveys thus largely exaggerate the impact of changes in the labour income distribution, while they undermine the capital share and its dynamics. As a reference, in a panel of nineteen countries, households collect half of total capital income, as opposed to corporations; but surveys only capture close to twenty percent of that half, versus seventy percent of total labour income. For any quantile group –e.g. the top 10% or bottom 50% share– a unit increase of its labour income share translates into an increase of nine tenths of a unit in the overall share, for capital income, the effect is only one tenth of a unit. Gaps are narrower but still present in tax data.
Journal Article
Direct comparison of spectral-domain and swept-source OCT in the measurement of choroidal thickness in normal eyes
2014
Objective To compare spectral-domain optic coherence tomography (SD-OCT) and swept-source OCT (SS-OCT) in the study of choroidal thickness (CT) in healthy eyes. Methods Prospective, cross-sectional, single-centre study. 82 healthy eyes of 46 patients were included. In a single session, Topcon 3D-2000 SD-OCT and 1050 nm SS-OCT prototype devices were used to perform OCT scans using a single line protocol. Two masked investigators independently, manually determined 13 CT measurements consisting of one subfoveal (SFCT), and six measurements on either side of the fovea (nasal and temporal) taken every 500 microns apart. The mean CT (MCT) was the mean average of these 13 measurements. Results SD-OCT was able to reproducibly measure the CT in 74.4% of eyes vs 100% with SS-OCT (p<0.05; Fisher's Exact test). In those eyes measured by both systems, mean SFCT was 279.4±96.9 μm (range, 84–506) with SD-OCT vs 285.7±88.9 μm (range 130–527) with SS-OCT (p=0.11; Student's t test paired data). Mean MCT was 243.8±78.8 μm (range 103.6–433.2) with SD-OCT vs 242.2±81.8 μm (range 97.6–459) with SS-OCT (p=0.64; Student's t test paired data). The difference in SFCT and MCT was not statistically significant between both devices. Intraclass correlation coefficient was higher than 0.9 interobserver and interdevice measurements. SFCT Bland–Altman plots showed 95% interobserver measurement agreement within ±34 for SD-OCT, ±22 for SS-OCT and ±60 μm intersystems. Conclusions SS-OCT permitted accurate identification of the choroido-scleral border in 100% of normal eyes, suggesting that SS-OCT was the superior modality for the measurement of CT.
Journal Article
Perceptions of COVID-19 patients in the use of bioethical principles and the physician-patient relationship: a qualitative approach
by
Cantú Quintanilla, Guillermo
,
Jaramillo Flores, Ignacio David
,
Aguiñaga-Chiñas, Nuria
in
Beliefs, opinions and attitudes
,
Bioethics
,
COVID-19
2024
Background
The COVID-19 pandemic has influenced the approach to the health-disease system, raising the question about the principles of bioethics present in physician–patient relations. The principles while widely accepted may not be sufficient for a comprehensive ethical analysis. Therefore, the aim of this study was to explore the perception of these principles and the physician–patient relationship during a hospital stay through a qualitative approach.
Method
Sixteen semi-structured interviews took place to know the patients’ perception during their 2020 hospitalization for COVID-19. The data was analyzed through the constant comparison method, creating categories and comparing them. In the end, seven categories were established and were grouped in three: bioethical principles (dignity, charity, vulnerability, autonomy), doctor-patient relationship (participant commitment, informed consent, health staff-patient relationship) and the experience of the disease (illness, the role of the family).
Results
The research found that most patients described a positive experience, with the feeling of having been well cared for with no sense of discrimination or injustice done. The majority also reported that their autonomy was respected in the treatment decisions. The evaluation of these attitudes is an area of opportunity, especially when the patients' vulnerability is at risk.
Conclusions
The ethics of virtue offers a better reflection of how human beings manifest themselves by emphasizing the development of virtuous character and behaviors that allow them to realize their values in life. Authorized by the Research Ethics Committee with registration: DI/18/105-B/3/308.
Journal Article
Early Detection of the Fungal Banana Black Sigatoka Pathogen Pseudocercospora fijiensis by an SPR Immunosensor Method
by
Carrillo-Pech, Mildred
,
Luna-Moreno, Donato
,
Canto-Canche, Blondy
in
Ascomycota - isolation & purification
,
Ascomycota - pathogenicity
,
Biosensing Techniques - methods
2019
Black Sigatoka is a disease that occurs in banana plantations worldwide. This disease is caused by the hemibiotrophic fungus Pseudocercospora fijiensis, whose infection results in a significant reduction in both product quality and yield. Therefore, detection and identification in the early stages of this pathogen in plants could help minimize losses, as well as prevent the spread of the disease to neighboring cultures. To achieve this, a highly sensitive SPR immunosensor was developed to detect P. fijiensis in real samples of leaf extracts in early stages of the disease. A polyclonal antibody (anti-HF1), produced against HF1 (cell wall protein of P. fijiensis) was covalently immobilized on a gold-coated chip via a mixed self-assembled monolayer (SAM) of alkanethiols using the EDC/NHS method. The analytical parameters of the biosensor were established, obtaining a limit of detection of 11.7 µg mL−1, a sensitivity of 0.0021 units of reflectance per ng mL−1 and a linear response range for the antigen from 39.1 to 122 µg mL−1. No matrix effects were observed during the measurements of real leaf banana extracts by the immunosensor. To the best of our knowledge, this is the first research into the development of an SPR biosensor for the detection of P. fijiensis, which demonstrates its potential as an alternative analytical tool for in-field monitoring of black Sigatoka disease.
Journal Article