Search Results (31)

This work presents an alternative method for defining feasible joint-space boundaries and their corresponding geometric workspace in a planar robotic system. Instead of relying on traditional numerical approaches that require extensive sampling and collision detection, the proposed method constructs a continuous boundary by identifying the key intersection points of boundary functions. The feasibility region is further refined through centroid-based scaling, addressing singularity issues and ensuring a well-defined trajectory. Comparative analyses demonstrate that the final robot pose and reachability depend on the selected traversal path, highlighting the nonlinear nature of the workspace. Additionally, an evaluation of traditional numerical methods reveals their limitations in generating continuous boundary trajectories. The proposed approach provides a structured method for defining feasible workspaces, improving trajectory planning in robotic systems. Full article

Maize plays a crucial role in global nutrition and food security, with Mexico making a significant contribution through its diverse native corn genotypes. However, research on flours derived from these native maize genotypes remains limited, hindering their potential applications in food manufacturing. This study aimed to determine the nutritional, physicochemical, techno-functional, structural, and antioxidant properties of corn kernel flours from nine native Mexican maize accessions cultivated in the highlands of Jalisco. Enough cobs for each maize accession were randomly selected to yield 1000 g of corn kernels. Data analysis was conducted by analysis of variance and Kruskal–Wallis tests (α = 0.05). Moreover, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were performed. Native corn kernel flour (NCKF) demonstrated higher protein and fat content compared to white hybrid corn flour (WHF). While both flours showed similar pH, titratable acidity, and water activity levels, NCKF exhibited higher total soluble solids. Additionally, NCKF showed superior techno-functional properties, including water solubility, water absorption index, swelling power, emulsifying capacity, and foaming capacity, while its oil absorption index was comparable to that of WHF. Moreover, NCKF contained higher levels of bioactive compounds, such as soluble phenols, condensed tannins, flavonoids, anthocyanins, and carotenoids, along with enhanced antioxidant properties, as measured by FRAP, DPPH, and ABTS assays. FTIR analysis revealed that all NCKF samples exhibited patterns similar to those of WHF with differences in transmittance intensities. Notably, spectral differences were identified by PCA, while HCA demonstrated that corn flours exhibited similitudes and differences among them, which can be categorized into four groups based on their nutritional, physicochemical, and technological–functional properties, as well as antioxidant compound contents. Overall, the evaluated corn flours displayed nutritional, physicochemical, techno-functional, and antioxidant properties for the potential development of functional or nutraceutical food and beverage products. Full article

This study focused on optimizing ultrasound-assisted extraction (UAE) conditions (X_PC: pulse cycle of 1:1, 2:1, and 3:1 s on/off; X_UP: ultrasound power of 80, 90, and 100%; and X_ET: extraction time of 2, 4, and 6 min) for maximizing the content of soluble phenols (TSPs) and flavonoids (FLAs) from a native Mexican pigmented corn kernel powder through response surface methodology (RSM). Under the Box–Behnken design conditions, the UAE of TSPs ranged from 27.72 to 34.87 mg/g, while FLA content ranged from 16.59 to 27.28 mg/g. The highest content for TSPs was under 4 min X_ET, 1:1 s on/off X_PC, and 100% X_UP, while for flavonoids it was under 6 min X_ET, 2:1 s on/off X_PC, and 80% X_UP. According to RSM analysis, the optimal UAE conditions for TSPs were found to be X_ET 3.15 min, 1.58 s on/off X_PC, and 100% X_UP, and an X_ET of 4.18 min, 3 s on/off X_PC, and 80% X_UP were the best experimental conditions for FLAs with a predictive TSP of 35.07 mg/g and FLA of 27.51 mg/g. These data were adjusted in a second-order polynomial model and experimentally validated (TSP = 34.06 mg/g and 27.04 mg/g). Furthermore, the extracts demonstrated antioxidant activity (ABTS, FRAP, and DPPH methods) for optimal UAE for TSPs and FLAs. The antioxidant extract from the native Mexican pigmented corn kernel powder can be used for diverse industrial applications. Thus, the UAE is an effective and sustainable technology for recovering bioactive compounds from maize-based materials. Full article

Sotol (Dasylirion leiophyllum) grows in the Chihuahan Desert in the north of Mexico and south of the United States. The stem of this species is used to produce a liquor widely known as sotol. A field sampling and a laboratory analysis were carried out to determine the influence of the rainy season, altitude, topography, and aspect over the soluble solid content (°Brix) and bromatological variables of mature plants of sotol in Chihuahua, Mexico. Analyses of variance and Tukey tests were performed. The rainy season and altitude showed significant statistical influence (p ≤ 0.05) on the total soluble solids content; meanwhile, only altitude showed a significant effect on the bromatological variables (p ≤ 0.05). According to the results of the Tukey tests (p < 0.05), sotol plants have the highest concentrations of soluble solid contents before the rainy season (25 °Brix) and at sites with altitudes lower than 1300 m (25.95 °Brix). In addition, the means of raw protein and carbohydrates content were the highest in plants living at altitudes lower than 1500 m, at 1.93% and 31.74%, respectively. Meanwhile, topography, aspect, and the interactions of the evaluated factors did not show significant influence (p ≤ 0.05) over the total soluble solid content, nor over the bromatological variables studied. Full article

Zika virus (ZIKV) is an emerging flavivirus that represents significant public health challenges, particularly in the Americas, and is a substantial risk to other parts of the world due to its rapid expansion and its established association with neurological disorders, including Guillain–Barré syndrome and an intrauterine fetal infection that can cause microcephaly, blindness, and other congenital neurological complications. To date, no vaccine to prevent ZIKV infections has been approved. Therefore, developing a safe and effective vaccine against this virus is a global health priority. This review analyzes the ZIKV outbreaks, as well as associated neurological complications, its genome, and immunological responses. The current vaccines in development have reported results from preclinical and clinical trials about novel approaches to obtain safer and more effective vaccines and the challenges faced by ZIKV vaccine development. Full article

The metabolic reprogramming that promotes tumorigenesis in glioblastoma is induced by dynamic alterations in the hypoxic tumor microenvironment, as well as in transcriptional and signaling networks, which result in changes in global genetic expression. The signaling pathways PI3K/AKT/mTOR and RAS/RAF/MEK/ERK stimulate cell metabolism, either directly or indirectly, by modulating the transcriptional factors p53, HIF1, and c-Myc. The overexpression of HIF1 and c-Myc, master regulators of cellular metabolism, is a key contributor to the synthesis of bioenergetic molecules that mediate glioma cell transformation, proliferation, survival, migration, and invasion by modifying the transcription levels of key gene groups involved in metabolism. Meanwhile, the tumor-suppressing protein p53, which negatively regulates HIF1 and c-Myc, is often lost in glioblastoma. Alterations in this triad of transcriptional factors induce a metabolic shift in glioma cells that allows them to adapt and survive changes such as mutations, hypoxia, acidosis, the presence of reactive oxygen species, and nutrient deprivation, by modulating the activity and expression of signaling molecules, enzymes, metabolites, transporters, and regulators involved in glycolysis and glutamine metabolism, the pentose phosphate cycle, the tricarboxylic acid cycle, and oxidative phosphorylation, as well as the synthesis and degradation of fatty acids and nucleic acids. This review summarizes our current knowledge on the role of HIF1, c-Myc, and p53 in the genic regulatory network for metabolism in glioma cells, as well as potential therapeutic inhibitors of these factors. Full article

Sotol (Dasylirion leiophyllum) is a shrubby species that grows in the Chihuahuan Desert. Sotol plants are commonly used to produce an alcoholic beverage, also known as “sotol”. A study was carried out to assess the composition and structure of shrubby communities where sotol inhabits in northern Mexico. The importance value index (IVI), diversity indexes, and structural attributes of the sotol community were estimated. Furthermore, a principal component and a cluster analysis were conducted in order to identify possible associations of species along the sotol distribution area. A total of 10,273 plants belonging to 17 families and 46 species were recorded, where the Agave lechuguilla and Tiquilia greggi were the most abundant species. Higher abundances of sotol and higher diversity indexes were observed in hillside areas and eastern aspects. The multivariate analyses revealed five shrubby groups in the distribution area of sotol, which grows in valleys, hillsides, and also on the top of mountains. The main communities found where sotol grows are rosetophyllous, microphyllous, and mesquite communities, and also, in higher altitudes, sotol is associated with oak species. This information is not only useful for a better species knowledge, but also for the protection of shrubby communities where Dasylirion leiophyllum inhabits. Full article

PET/CT scanners with a long axial field-of-view (LAFOV) provide increased sensitivity, enabling the adjustment of imaging parameters by reducing the injected activity or shortening the acquisition time. This study aimed to evaluate the limitations of reduced [¹⁸F]FDG activity doses on image quality, lesion detectability, and the quantification of lesion uptake in the Biograph Vision Quadra, as well as to assess the benefits of the recently introduced ultra-high sensitivity mode in a clinical setting. A number of 26 patients who underwent [¹⁸F]FDG-PET/CT (3.0 MBq/kg, 5 min scan time) were included in this analysis. The PET raw data was rebinned for shorter frame durations to simulate 5 min scans with lower activities in the high sensitivity (HS) and ultra-high sensitivity (UHS) modes. Image quality, noise, and lesion detectability (n = 82) were assessed using a 5-point Likert scale. The coefficient of variation (CoV), signal-to-noise ratio (SNR), tumor-to-background ratio (TBR), and standardized uptake values (SUV) including SUV_mean, SUV_max, and SUV_peak were evaluated. Subjective image ratings were generally superior in UHS compared to the HS mode. At 0.5 MBq/kg, lesion detectability decreased to 95% (HS) and to 98% (UHS). SNR was comparable at 1.0 MBq/kg in HS (5.7 ± 0.6) and 0.5 MBq/kg in UHS (5.5 ± 0.5). With lower doses, there were negligible reductions in SUV_mean and SUV_peak, whereas SUV_max increased steadily. Reducing the [¹⁸F]FDG activity to 1.0 MBq/kg (HS/UHS) in a LAFOV PET/CT provides diagnostic image quality without statistically significant changes in the uptake parameters. The UHS mode improves image quality, noise, and lesion detectability compared to the HS mode. Full article

Kinematics is a fundamental topic in engineering, robotics, mechatronics, and control systems and significantly resolves some of these fields’ most pressing issues. It is essential to assess the balance between a topic’s theoretical framework and its empirical validation to succeed in engineering. Educational tools have gained significant attention for their ability to enhance the learning experience by providing the hands-on experiences necessary to assess theoretical frameworks and empirical validations. This paper presents a system incorporating state-of-the-art features, including a fuzzy controller enabling precise control of a linear actuator and a USB camera, to provide an interactive experience. The USB camera captures the position of the actuator, providing real-time visual feedback and allowing the students to validate their theoretical understanding through practical experiments. Precision, accuracy, resolution, and the implementation of the fuzzy controller are measured to evaluate the whole system’s performance. The design, implementation, and control of our educational electrical linear actuator for teaching kinematics concepts contribute to a practical educational tool and advance interactive learning approaches in the field. Full article

Background: Static [¹⁸F]FDG-PET/CT is the imaging method of choice for the evaluation of indeterminate lung lesions and NSCLC staging; however, histological confirmation of PET-positive lesions is needed in most cases due to its limited specificity. Therefore, we aimed to evaluate the diagnostic performance of additional dynamic whole-body PET. Methods: A total of 34 consecutive patients with indeterminate pulmonary lesions were enrolled in this prospective trial. All patients underwent static (60 min p.i.) and dynamic (0–60 min p.i.) whole-body [¹⁸F]FDG-PET/CT (300 MBq) using the multi-bed-multi-timepoint technique (Siemens mCT FlowMotion). Histology and follow-up served as ground truth. Kinetic modeling factors were calculated using a two-compartment linear Patlak model (FDG influx rate constant = Ki, metabolic rate = MR-FDG, distribution volume = DV-FDG) and compared to SUV using ROC analysis. Results: MR-FDG_mean provided the best discriminatory power between benign and malignant lung lesions with an AUC of 0.887. The AUC of DV-FDG_mean (0.818) and SUV_mean (0.827) was non-significantly lower. For LNM, the AUCs for MR-FDG_mean (0.987) and SUV_mean (0.993) were comparable. Moreover, the DV-FDG_mean in liver metastases was three times higher than in bone or lung metastases. Conclusions: Metabolic rate quantification was shown to be a reliable method to detect malignant lung tumors, LNM, and distant metastases at least as accurately as the established SUV or dual-time-point PET scans. Full article

The tropical montane cloud forest in Mexico is the most diverse and threatened ecosystem. Mexican macrofungi numbers more than 1408 species. This study described four new species of Agaricomycetes (Bondarzewia, Gymnopilus, Serpula, Sparassis) based on molecular and morphological characteristics. Our results support that Mexico is among the most biodiverse countries in terms of macrofungi in the Neotropics. Full article

Agro-industrial wastes such as wheat husk (WH) are renewable sources of organic and inorganic substances, including cellulose, lignin, and aluminosilicates, which can be transformed into advanced materials with high added value. The use of geopolymers is a strategy to take advantage of the inorganic substances by obtaining inorganic polymers, which have been used as additives, e.g., for cement and refractory brick products or ceramic precursors. In this research, the WH native to northern Mexico was used as a source to produce wheat husk ash (WHA) following its calcination at 1050 °C. In addition, geopolymers were synthesized from the WHA by varying the concentrations of the alkaline activator (NaOH) from 16 M to 30 M, namely Geo 16M, Geo 20M, Geo 25M, and Geo 30M. At the same time, a commercial microwave radiation process was employed as the curing source. Furthermore, the geopolymers synthesized with 16 M and 30 M of NaOH were studied for their thermal conductivity as a function of temperature, in particular at 25, 35, 60, and 90 °C. The chemical composition of the WHA, determined by ICP, revealed a SiO₂ content close to 81%, which is similar to rice husk. The geopolymers were characterized using various techniques to determine their structure, mechanical properties, and thermal conductivity. The findings showed that the synthesized geopolymers with 16M and 30M of NaOH had significant mechanical properties and thermal conductivity, respectively, compared to the other synthesized materials. Finally, the thermal conductivity regarding the temperature revealed that Geo 30M presented significant performance, especially at 60 °C. Full article

The biochemical composition, molecular diversity, and two different bioactivities of Asparagopsis armata and Rugulopteryx okamurae (two alien species with different invasive patterns in the southern Iberian Peninsula) were analyzed through spectrophotometric methods and Fourier transform ion cyclotron mass spectroscopy (FT-ICR-MS). A total of 3042 molecular formulas were identified from the different extracts. The _dH₂O extracts were the most molecularly different. A. armata presented the highest content of nitrogenous compounds (proteins, CHON) and sulphur content, whereas R. okamurae was rich in carbonated compounds (total carbon, lipids, CHO, and CHOP). Antioxidant capacity and phenolic content were higher in R. okamurae than in A. armata. Antimicrobial activity was detected from both species. A. armata showed capacity to inhibit human and fish pathogens (e.g., Staphylococcus aureus or Vibrio anguillarum), whereas R. okamurae only showed inhibition against human bacteria (Staphylococcus aureus and Cutibacterium acnes). In R. okamurae, molecules with a great number of pharmaceutical activities (e.g., anti-inflammatory or antitumoral), antibacterial, biomaterial, and other utilities were found. The main molecules of A. armata had also pharmaceutical applications (e.g., antimalarian, antithrombotic, anti-inflammatory, or antiarthritis). The valorization of these species can help to counteract the environmental effects of the bioinvasions. Full article

The health-related quality of life (HRQoL) of the patients cared for with teledermatology (TD) services was analyzed as compared with face-to-face dermatology (F-F/D) at the hospital. This study was a controlled, non-blinded, intra-level, and multicenter randomized clinical trial, with a 6-month follow-up. A total of 450 patients were randomly assigned to two different groups. The Spanish version of the generic EuroQol-5-dimensions-5-Levels (EQ-5D-5L) questionnaire and the specific Skindex-29 questionnaire were used at 0 and 6 months. The number of primary care visits (2.24 TD; 1.68 F-F/D) and number of hospital visits (0.01 TD; 1.48 F-F/D) were statistically significant. It was observed that from month 0 onwards, the users included in the F-F/D group self-perceived a lower HRQoL than the users included in the TD group (Skindex-29 total: p ≤ 0.00; EQ-5D-5L VAS = p ≤ 0.00; EQ-5D-5L utilities = p ≤ 0.00). At the end of the study, the patients included in the F-F/D group still obtained lower scores in their perception of HRQoL, as compared to those included in the other type of follow-up (Skindex-29 total: p ≤ 0.00; EQ-5D-5L VAS = p ≤ 0.00; EQ-5D-5L utilities = p ≤ 0.00). TD was an effective diagnosis and follow-up tool. At the end of the study period, the HRQoL of the patients in both groups was significantly higher as compared to their baseline levels. Additionally, both the general and specific HRQoL perceived by the TD patients was higher than the F-F/D group from the start of the study. Full article

Glioblastomas are incurable primary brain tumors harboring a heterogeneous landscape of genetic and metabolic alterations. Longitudinal imaging by MRI and [¹⁸F]FET-PET measurements enable us to visualize the features of evolving tumors in a dynamic manner. Yet, close-meshed longitudinal imaging time points for characterizing temporal and spatial metabolic alterations during tumor evolution in patients is not feasible because patients usually present with already established tumors. The replication-competent avian sarcoma-leukosis virus (RCAS)/tumor virus receptor-A (tva) system is a powerful preclinical glioma model offering a high grade of spatial and temporal control of somatic gene delivery in vivo. Consequently, here, we aimed at using MRI and [¹⁸F]FET-PET to identify typical neuroimaging characteristics of the platelet-derived growth factor B (PDGFB)-driven glioma model using the RCAS-tva system. Our study showed that this preclinical glioma model displays MRI and [¹⁸F]FET-PET features that highly resemble the corresponding established human disease, emphasizing the high translational relevance of this experimental model. Furthermore, our investigations unravel exponential growth dynamics and a model-specific tumor microenvironment, as assessed by histology and immunochemistry. Taken together, our study provides further insights into this preclinical model and advocates for the imaging-stratified design of preclinical therapeutic interventions. Full article