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501 result(s) for "Aguilar, Alfredo"
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Plants Used in Mexican Traditional Medicine for the Management of Urolithiasis: A Review of Preclinical Evidence, Bioactive Compounds, and Molecular Mechanisms
Urolithiasis (UL) involves the formation of stones in different parts of the urinary tract. UL is a health problem, and its prevalence has increased considerably in developing countries. Several regions use plants in traditional medicine as an alternative in the treatment or prevention of UL. Mexico has known about the role of traditional medicine in the management of urinary stones. Mexican traditional medicine uses plants such as Argemone mexicana L., Berberis trifoliata Hartw. ex Lindl., Costus mexicanus Liebm, Chenopodium album L., Ammi visnaga (L.) Lam., Eysenhardtia polystachya (Ortega) Sarg., Selaginella lepidophylla (Hook. & Grev.) Spring, and Taraxacum officinale L. These plants contain different bioactive compounds, including polyphenols, flavonoids, phytosterols, saponins, furanochromones, alkaloids, and terpenoids, which could be effective in preventing the process of stone formation. Evidence suggests that their beneficial effects might be associated with litholytic, antispasmodic, and diuretic activities, as well as an inhibitory effect on crystallization, nucleation, and aggregation of crystals. The molecular mechanisms involving these effects could be related to antioxidant, anti-inflammatory, and antimicrobial properties. Thus, the review aims to summarize the preclinical evidence, bioactive compounds, and molecular mechanisms of the plants used in Mexican traditional medicine for the management of UL.
Relationship between lipid accumulation product and oxidative biomarkers by gender in adults from Yucatan, Mexico
Excessive adipose tissue can lead to metabolic abnormalities resulting in lipid alteration and oxidative stress (OS) status. The lipid accumulation product (LAP) index is a biomarker that indicates central lipid accumulation and has been proposed as an accurate and independent indicator of risk for several cardiometabolic related conditions. There is a lack of information about the possible association of LAP and OS biomarkers. Therefore, this work aimed to investigate the relationship between LAP and OS biomarkers in adults. A cross-sectional study was performed in 250 subjects attending the Hospital Regional de Alta Especialidad de la Península de Yucatán. Anthropometrical and clinical parameters were measured. The serum oxidative biomarkers such as malondialdehyde (MDA) and total antioxidant capacity (TAC) were evaluated by spectrophotometry and by the oxygen radical absorbance capacity (ORAC), respectively. A positive and significant correlation between serum levels of MDA and LAP (r = 0.162, p = 0.010) was observed. This relationship was stronger in women (r = 0.189, p = 0.013) than in men. The association between them remained significant after adjusting for confounders (r = 0.23, p < 0.001). A cutoff of LAP of 73.73 predicts high levels of MDA in women aged between 40 and 59. LAP index was associated with OS biomarkers in women and men from Yucatan, Mexico. Therefore, the elevation of the LAP index could identify an imbalance in the redox status.
Lag Phase in the Anaerobic Co-Digestion of Sargassum spp. and Organic Domestic Waste
The mass arrival of pelagic sargassum is an international issue that is currently taking its toll on the economic activity of affected regions by causing a significant reduction in investment and tourism. The purpose of this work was to evaluate the Logistic Modified and Gompertz Modified sigmoid kinetic models for describing the lag phase in the generation of biomethane. The case studies were: anaerobic co-digestion (ACoD) of Sargassum spp./domestic organic waste and Sargassum spp. in mono-digestion. The experimental method, based on biochemical methane potential (BMP), enabled kinetic models to be built for methane production under environmental conditions and an estimate to be made for the duration of the lag phase. The maximum cumulative production determined for monodigestion was 140.7 cm3 of CH4/g SV at 99 days, and for ACoD, it was 161.3 cm3 of CH4/g SV at 172 days. The lag phase was determined to be approximately 7 days and 93 days, respectively. It was concluded that the modified sigmoid growth functions are a valuable tool for studying the start-up and scaling of systems for the ACoD of organic waste. The results present the ACoD of coastal pelagic sargassum algae and domestic organic waste as a potential alternative energy source.
Effect of CCL5 expression in the recruitment of immune cells in triple negative breast cancer
Triple negative breast cancer (TNBC) is the most aggressive form of breast cancer with limited options of targeted therapy. Recent findings suggest that the clinical course of TNBC may be modified by the presence of tumor-infiltrating lymphocytes (TILs) and chemokine’s expression, such as CCL5 . Diverse studies have shown that CCL5 suppresses anti-tumor immunity and it has been related to poor outcome in different types of cancer while in other studies, this gene has been related with a better outcome. We sought to determine the association of CCL5 with the recruitment of TILs and other immune cells. With this aim we evaluated a retrospective cohort of 72 TNBC patients as well as publicly available datasets. TILs were correlated with residual tumor size after neoadjuvant chemotherapy (NAC) and CCL5 expression. In univariate analysis, TILs and CCL5 were both associated to the distant recurrence free survival; however, in a multivariate analysis, TILs was the only significant marker (HR = 0.336; 95%IC: 0.150–0.753; P = 0.008). CIBERSORT analysis suggested that a high CCL5 expression was associated with recruitment of CD8 T cells, CD4 activated T cells, NK activated cells and macrophages M1. The CD8A gene (encoding for CD8) was associated with an improved outcome in several public breast cancer datasets.
Development of an Analytical Model for Optimization of Direct Laser Interference Patterning
Direct laser interference patterning (DLIP) has proven to be a fast and, at the same time, high-resolution process for the fabrication of large-area surface structures. In order to provide structures with adequate quality and defined morphology at the fastest possible fabrication speed, the processing parameters have to be carefully selected. In this work, an analytical model was developed and verified by experimental data, which allows calculating the morphological properties of periodic structures as a function of most relevant laser-processing parameters. The developed model permits to improve the process throughput by optimizing the laser spot diameter, as well as pulse energy, and repetition rate. The model was developed for the structures formed by a single scan of the beam in one direction. To validate the model, microstructures with a 5.5 µm spatial period were fabricated on stainless steel by means of picosecond DLIP (10 ps), using a laser source operating at a 1064 nm wavelength. The results showed a difference of only 10% compared to the experimental results.
Fabrication of inclined non-symmetrical periodic micro-structures using Direct Laser Interference Patterning
The direct fabrication of microstructures, having a non-symmetrical morphology with controllable inclination, presents nowadays a challenging task. Natural examples of surfaces with inclined topographies have shown to provide anisotropic functionalities, which have attracted the interest of several researchers in the last years. This work presents a microfabrication technique for producing microstructures with a determined and controllable inclination angle using two-beam Direct Laser Interference Patterning. Polyimide foils are irradiated with a 4 ns UV (266 nm) laser source producing line-like structures with a period varying from 4.6 µm to 16.5 µm. The inclinations, retrieved by tilting the sample with respect to the optical axis of the setup, are changed from 0° to 75°, introducing a well controllable and defined inclination of the structure walls. The structuring parameters (laser fluence, number of laser pulses and interference period) as well as the inclination of the microstructures are correlated with the global tilting of the sample. As a result, a determined laser fluence and number of pulses are necessary to observe a remarkable non-symmetrical morphology of the structures. In addition, the presence of structural undercuts is reported, which opens the possibility for developing new direction-dependent properties on polymeric materials. As an example, preliminary results on light diffraction are presented, showing a similar behavior as blazed diffraction gratings.
Schwarzschild black hole and redshift rapidity: a new approach towards measuring cosmic distances
Motivated by recent achievements of a full general relativistic method in estimating the mass-to-distance ratio of supermassive black holes hosted at the core of active galactic nuclei, we introduce the new concept redshift rapidity in order to express the Schwarzschild black hole mass and its distance from the Earth just in terms of observational quantities. The redshift rapidity is also an observable relativistic invariant that represents the evolution of the frequency shift with respect to proper time in the Schwarzschild spacetime. We extract concise and elegant analytic formulas that allow us to disentangle mass and distance to black holes in the Schwarzschild background and estimate these parameters separately. This procedure is performed in a completely general relativistic way with the aim of improving the precision in measuring cosmic distances to astrophysical compact objects. Our exact formulas are valid on the midline and close to the line of sight, having direct astrophysical applications for megamaser systems, whereas the general relations can be employed in black hole parameter estimation studies. We also computed the frequency shift and the redshift rapidity for emitter eccentric orbits and calculated their relative error with respect to their numerical exact value for different eccentricities.
Effect of the SiO2 support morphology on the hydrodesulfurization performance of NiMo catalysts
To study the effects of the support morphology on the hydrodesulfurization (HDS) activity of NiMoS catalysts, ordered mesoporous SiO2 (KIT-6) and nonporous nanospheres of SiO2 were used as supports. Metal species (Ni and Mo) were incorporated through a sequential impregnation technique. The aqueous solution of nickel nitrate was introduced first on the supports, followed by the solution of ammonium molybdate. Subsequently, a sulfidation treatment was carried out in gaseous H2S/H2 atmosphere. The NiMo/Al2O3 commercial catalyst was used as reference. The materials obtained were characterized by N2 physisorption, X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM) and evaluated in the HDS catalytic reaction of dibenzothiophene in a batch reactor. The results indicate that the textural properties of KIT-6 were the key factors to obtain disperse NiMoS stacks, and a better metal sulfidation, which lead to a higher catalytic activity of the NiMo/KIT-6 catalyst (twice as active) compared to the NiMo/Nanosilica catalyst. In addition, the activity of the NiMo/KIT-6 catalyst was also superior to that obtained for the commercial catalyst.
In silico evaluation of DNA Damage Inducible Transcript 4 gene (DDIT4) as prognostic biomarker in several malignancies
DDIT4 gene encodes a protein whose main action is to inhibit mTOR under stress conditions whilst several in vitro studies indicate that its expression favors cancer progression. We have previously described that DDIT4 expression is an independent prognostic factor for tripe negative breast cancer resistant to neoadjuvant chemotherapy. We herein report that high DDIT4 expression is related to the outcome (recurrence-free survival, time to progression and overall survival) in several cancer types. We performed in silico analysis in online platforms, in pooled datasets from KM Plotter and meta-analysis of individual datasets from SurvExpress. High levels of DDIT4 were significantly associated with a worse prognosis in acute myeloid leukemia, breast cancer, glioblastoma multiforme, colon, skin and lung cancer. Conversely, a high DDIT4 expression was associated with an improved prognostic in gastric cancer. DDIT4 was not associated with the outcome of ovarian cancers. Analysis with data from the Cell Miner Tool in 60 cancer cell lines indicated that although rapamycin activity was correlated with levels of MTOR , it is not influenced by DDIT4 expression. In summary, DDIT4 might serve as a novel prognostic biomarker in several malignancies. DDIT4 activity could be responsible for resistance to mTOR inhibitors and is a potential candidate for the development of targeted therapy.
Observational redshift from general spherically symmetric black holes
In this work, we obtain an expression for the total observational frequency shift of photons emitted by massive geodesic particles circularly orbiting a black hole in a general spherically symmetric background. Our general relations are presented in terms of the metric components and their derivatives that characterize the black hole parameters. As a concrete example of this general relativistic approach, a special case is studied by applying the formalism to a nonsingular black hole conformally related to the Schwarzchild solution that possesses a length scale parameter l and an integer parameter N in addition to the black hole mass. Besides, we express the nonsingular black hole mass in terms of the observational redshift/blueshift. Finally, we investigate the effects of the free parameters of the conformal gravity theory on the observational frequency shift and compare results with those of the standard Schwarzschild black hole.