The Mayan cichlid (Cichlasoma urophthalmus), is a freshwater fish of the Cichlidae family, native to the south east of Mexico, it has potential for extensive cultivation due to its excellent meat ...quality and local demand. However, the nutrigenomic aspects and molecular expression of genes involved in its digestion that could contribute to its growth during the larval stage are unknown. Some enzymes such as Pepsin (PEP), pancreatic such as trypsin (TRY), Chymotrypsin CHY and intestinal enzymes such as Leucine aminopeptidase ANPEP, function during larval ontogenesis and activity patterns of the key factors involved in the digestive system. For this study, 30–50 larvae were collected, which were processed with mRNA extraction techniques and cDNA synthesis by RT‐PCR using qPCR oligos designed from Oreochromis niloticus, measuring molecular expression during the initial ontogeny of C. urophthalmus. The results obtained show the molecular expression of these enzymes occurs through epigenetic factors such as changes from endogenous to exogenous feeding, presenting the activation of genes for the formation of organs of the digestive tract that allow the secretion of specific enzymes for processing and digestion of food, that can activate these genes to increase the digestion efficiency and the optimal use of nutrients.
The tropical gar (Atractosteus tropicus) is one of the most important commercial species in south‐eastern Mexico, being studied in reproductive, physiological, nutrition and cultivation aspects; ...however, the aspects related to the endocrine system are unknown, mainly the expression of hormones during their larval development. In this study, we investigated the expression of the insulin gene (INS) and growth hormone (GH), during the embryonic period (egg), eleutheroembryon (3 DAH) up to 25 DAH using RTq‐PCR, normalized with the elongation factor gene EF1‐α. The INS phylogenetic inference showed an amino acid identity of 97%, while GH 99% against the sequence of Lepisosteus oculatus, indicating that these species are related and come from a common ancestor. The gene expression of the INS showed four peaks at 3, 7, 11 and 19 DAH, corresponding to changes in diet (Artemia nauplii) and artificial foods. GH expression was detected from the egg, increasing from day 15 to 25 DDE, concluding that A. tropicus larvae showed early and high expressions of these hormones, indicating a direct relationship with changes in metabolism of the species, increasing its function according to the nutrients present in the food and the increase in growth during the ontogeny of A. tropicus.
The Use of Zinc Oxide in Asphalts: Review Rondón-Quintana, Hugo Alexander; Ruge-Cárdenas, Juan Carlos; Zafra-Mejía, Carlos Alfonso
Sustainability,
07/2023, Letnik:
15, Številka:
14
Journal Article
Recenzirano
Odprti dostop
Zinc oxide (ZnO) is a wide-gap semiconducting material which is chemically stable at high temperatures and has been shown to be compatible with asphalt binders. Additionally, semiconducting ...nanoparticles such as ZnO could help to improve urban air quality. This has encouraged the use of this material as a binder and asphalt mix modifier. A review on the use of ZnO as an asphalt binder modifier was conducted in this study. Based on the review which we carried out, the following were mainly synthesized and described: the content of ZnO as a modifier, the mixing processes of the binder and the ZnO, the manufacturing process of the modified mix, the type of asphalt binder and/or modified mix, the tests carried out, general conclusions, and environmental effects. ZnO micro-particles increase the aging resistance of the asphalt binder (mainly to ultraviolet radiation (UV)). ZnO tends to increase rutting resistance and adhesion with aggregates, improving resistance to moisture damage. It also tends to improve binder fatigue resistance. At low service temperatures, the performance of ZnO as a modifier is unclear, and further studies should be performed. Few studies have evaluated the effect of ZnO on the environment when it is used as an asphalt binder modifier. Future studies should evaluate the effect of this technology on the environment, perform economic analyses, evaluate the physical–chemical interaction of the modified binder with the aggregate, and measure the long-term properties of asphalt mixtures. ZnO is viewed as an environmentally friendly material and as a promising modifier of asphalt binders for pavement construction.
Objective
Examining orthopedic residents in Mexico, researchers explore the relationship between the presence of depressive or anxious symptoms and the degree of perfectionism, perceived work-related ...distress, and involvement in the care of patient(s) who died.
Methods
This was a cross-sectional online survey of 642 orthopedic residents from October 2019 to April 2021.
Results
Of orthopedic residents contacted, 50.6% responded rate (70.9% male, average age 29.8 years). A total of 12.5% reported significant depressive symptoms and 18.4% reported significant anxious symptoms. On a scale from 0-100, the mean score of perceived work-related distress was 51.9. One-third (33.6%) reported being involved in the care of patient(s) who had died. Higher levels of work-related distress and higher scores on perfectionism were associated with depressive and anxiety symptoms. In particular, being involved in the care of patient(s) who had died was associated with anxious symptoms (OR = 1.79; 95%CI = 1.18-2.72).
Conclusions
These results highlight the need for systematic monitoring of the mental health of orthopedic residents in Mexico, particularly those who report a high level of work-related distress or perfectionism or who have recently experienced the death of a patient.
Intentional bacterial infections can produce efficacious antitumor responses in mice, rats, dogs, and humans. However, low overall success rates and intense side effects prevent such approaches from ...being employed clinically. In this work, we titered bacteria and/or the proinflammatory cytokine TNFα in a set of established murine models of cancer. To interpret the experiments conducted, we considered and calibrated a tumor-effector cell recruitment model under the influence of functional tumor-associated vasculature. In this model, bacterial infections and TNFα enhanced immune activity and altered vascularization in the tumor bed. Information to predict bacterial therapy outcomes was provided by pretreatment tumor size and the underlying immune recruitment dynamics. Notably, increasing bacterial loads did not necessarily produce better long-term tumor control, suggesting that tumor sizes affected optimal bacterial loads. Short-term treatment responses were favored by high concentrations of effector cells postinjection, such as induced by higher bacterial loads, but in the longer term did not correlate with an effective restoration of immune surveillance. Overall, our findings suggested that a combination of intermediate bacterial loads with low levels TNFα administration could enable more favorable outcomes elicited by bacterial infections in tumor-bearing subjects.
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Natural Asphalts in Pavements: Review Rondón-Quintana, Hugo Alexander; Ruge-Cárdenas, Juan Carlos; Zafra-Mejía, Carlos Alfonso
Sustainability,
01/2023, Letnik:
15, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Natural asphalts (NAs) can be an economical and environmental alternative in pavement construction. Most studies have investigated them as binder and asphalt mixture modifiers due to their high ...compatibility with conventional asphalts. In this article, some of the studies carried out on the use of NA in pavements are summarized and described in a chronological order. The main aspects described in the reviewed studies were the type of asphalt binder or modified mixture, the type and content of the modifier, the manufacturing processes of the asphalt or modified mixture, tests performed, and main results or conclusions. In general terms, NAs show better performance as binder and asphalt mixture modifiers in high-temperature climates. Additionally, they tend to improve water and ageing resistance. As main limitations, it is reported that NAs tend to negatively affect the workability and performance of asphalt mixtures in low-temperature climates. Finally, recommendations for future study topics are provided at the end of this paper.
Microalgae, including cyanobacteria, represent a valuable source of natural compounds that have remarkable bioactive properties. Each microalga species produces a mixture of antioxidants with ...different amounts of each compound. Three aspects are important in the production of bioactive compounds: the microalga species, the medium composition including light supplied and the photobioreactor design, and operation characteristics. In this study, the antioxidant content and productivity performance of four microalgae were assessed in batch and continuous cultures. Biomass productivity by the four microalgae was substantially enhanced under continuous cultivation by 5.9 to 6.3 times in comparison with batch cultures. The energetic yield, under the experimental conditions studied, ranged from 0.03 to 0.041 g biomass kJ
. Phenols, terpenoids, and alkaloids were produced by
,
, and
, whereas tocopherols and carotenoids were produced by the four microalgae, except for phycocyanin and allophycocyanin, which were only produced by
and
. The findings demonstrate that the continuous cultivation of microalgae in photobioreactors is a convenient method of efficiently producing antioxidants.
Tropical gar (Atractosteus tropicus) is an ecologically, culturally, economically, and scientifically important species. Therefore, it is essential to know the available resources to design feeds for ...the culture of this species. This study evaluated the in vitro digestibility of meals and oils commonly used in aquaculture, using crude extract of the stomach and intestines of A. tropicus juveniles. We used the pH stat titration system to determine the degree of hydrolysis (DH%), the concentration of amino acids released (mg g of meal-1), and the speed of hydrolysis (SH%) of various animal and vegetable ingredients. The relative digestibility of each protein ingredient was calculated using bovine hemoglobin for acid digestion and Hammersten bovine casein for the alkaline phase as reference ingredients (100% digestibility). For lipid ingredients, fish oil was used as a reference. The highest relative digestibility for protein ingredients was observed with fish, crustaceans, beef, poultry meat and offal, and beef blood meals. The best lipid SH was observed with soybean lecithin and cod liver, soybean, olive, maize, and canola oils. It is possible to use a wide variety of terrestrial animal proteins and vegetable oils for manufacturing a diet for A. tropicus rearing.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes de COVID-19 disease use as a principal receptor the angiotensin-converting enzyme-2 (ACE2). It has been ...suggested that dipeptidyl peptidase-4 (DPP4) can be another possible receptor for this virus. The present study aimed to establish if the DPP4 levels and DPP4 polymorphisms are associated with COVID-19 disease and its severity.
The study included 107 COVID-19 patients and 263 matched-healthy controls. Fifty patients required invasive mechanical ventilation. The DPP4 was quantified in serum using the Bioplex system. Based on the previous results and the functional prediction analysis, we select for the study 5 DPP4 polymorphisms (rs12617336, rs12617656, rs1558957, rs3788979, and rs17574) and these were determined using the 5´exonuclease TaqMan assays.
Low levels of DPP4 were observed in COVID-19 patients (46.5 33.1–57.7 ng/mL) when compared to healthy controls (125.3 100.3–157.3 ng/mL) (P < 0.0001). Also, patients that required mechanical ventilation showed lower DPP4 levels (42.8 29.8–56.9 ng/mL) than those that did not need this procedure (49.2 39.9–65.6 ng/mL) (P = 0.012). DPP4 levels correlated negatively with age, fibrinogen, and platelet levels, and positively with albumin, alanine aminotransferase, and percentage of neutrophils. The DPP4 rs3788979 polymorphism was associated with a high risk of COVID-19 disease and, the TT genotype carriers had the lowest DPP4 levels.
In summary, in the present study, an association of low levels of DPP4 with COVID-19 disease and severity was found. The association of the DPP4 rs3788979 polymorphism with COVID-19 is also reported.
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