Search

PURPOSE: The aim of this study was to investigate, the neuroprotective effects of a new Gramine derivative named: ITH12657, in a model of retinal excitotoxicity induced by intravitreal injection of NMDA. METHODS: Adult Sprague Dawley rats received an intravitreal injection of 100 mM NMDA in their left eye and were treated daily with subcutaneous injections of ITH12657 or vehicle. The best dose-response, therapeutic window study, and optimal treatment duration of ITH12657 were studied. Based on the best survival of Brn3a + RGCs obtained from the above-mentioned studies, the protective effects of ITH12657 were studied in vivo (retinal thickness and full-field Electroretinography), and ex vivo by quantifying the surviving population of Brn3a + RGCs, αRGCs and their subtypes α-ONsRGCs, α-ONtRGCs, and α-OFFRGCs. RESULTS: Administration of 10 mg/kg ITH12657, starting 12 h before NMDA injection and dispensed for 3 days, resulted in the best significant protection of Brn3a + RGCs against NMDA-induced excitotoxicity. In vivo, ITH12657-treated rats showed significant preservation of retinal thickness and functional protection against NMDA-induced retinal excitotoxicity. Ex vivo results showed that ITH12657 afforded a significant protection against NMDA-induced excitotoxicity for the populations of Brn3a + RGC, αRGC, and αONs-RGC, but not for the population of αOFF-RGC, while the population of α-ONtRGC was fully resistant to NMDA-induced excitotoxicity. CONCLUSION: Subcutaneous administration of ITH12657 at 10 mg/kg, initiated 12 h before NMDA-induced retinal injury and continued for 3 days, resulted in the best protection of Brn3a + RGCs, αRGC, and αONs-RGC against excitotoxicity-induced RGC death. The population of αOFF-RGCs was extremely sensitive while α-ONtRGCs were fully resistant to NMDA-induced excitotoxicity.

This study aims to investigate two key aspects in a mouse model of ocular hypertension (OHT): first, the time course of retinal ganglion cell (RGC) death and the parallel activation of caspase-3 (a-Casp3+ cells) to narrow the therapeutic window; and second, the effect of caspase-3 and microglia inhibition by minocycline on RGC rescue in this model. RGC loss after OHT induction was significant at day 7 and progressed to 30 days. However, anatomical RGC death was preceded by significant Casp3 activation on day 3. Microglial inhibition by minocycline did not alter the course of OHT or rescue RGCs but resulted in a decrease in a-Casp3+ cells and phagocytic and total microglia. Therefore, RGC death commitment occurs earlier than their loss of Brn3a expression, microglial cells do not exacerbate RGC loss, and while this death is primarily apoptotic, apoptosis inhibition does not rescue RGCs, suggesting that alternative death pathways play a role in glaucomatous injury. [ABSTRACT FROM AUTHOR]

This study addresses the morphological and chemical characterization of PGS scaffolds after (6, 12, 18, 24, and 30 min) residence in undoped pyrrole plasma (PGS-PPy) and the evaluation of cell viability with human dental pulp stem cells (hDPSCs). The results were compared with a previous study that used iodine-doped pyrrole (PGS-PPy/I). Analyses through SEM and AFM revealed alterations in the topography and quantity of deposited PPy particles. FTIR spectra of PGS-PPy scaffolds confirmed the presence of characteristic absorption peaks of PPy, with higher intensities observed in the nitrile and -C≡C- groups compared to PGS-PPy/I scaffolds, while raman spectra indicated a lower presence of polaron N+ groups. On the other hand, PGS scaffolds modified with PPy exhibited lower cytotoxicity compared to PGS-PPy/I scaffolds, as evidenced by the Live/Dead assay. Furthermore, the PGS-PPy scaffolds at 6 and 12 min, and particularly the PGS-PPy/I scaffold at 6 min, showed the best results in terms of cell viability by the fifth day of culture. The findings of this study suggest that undoped pyrrole plasma modification for short durations could also be a viable option to enhance the interaction with hDPSCs, especially when the treatment times range between 6 min and 12 min. [ABSTRACT FROM AUTHOR]

A first-principles model of the anomalous momentum-transfer collision frequency for electrons ( v e a ) in E × B ion accelerators, also known as Hall-effect thrusters, is presented. The theory on which the model is based adopts a two-stage evolution of unstable waves. First, short-wavelength ( k ⊥ ρ e > 1), high-frequency ( ω ∼ ω c e ) modes that are driven by the cross-field drift υ E = E × B / B 2 grow and saturate at a level of turbulence too low to explain the observed measurements. Then, the wave energy is dominated by modes of longer wavelength ( k ⊥ ρ e < 1) and in the range of the lower-hybrid frequency ω L H = ω p i / 1 + ω p e 2 / ω c e 2 ½ . The lower-hybrid modes combine wave growth in the azimuthal direction that is driven by the diamagnetic drift υ D e = ∇ p e × B / e n B 2 , with growth parallel to B due to a higher effective mass of electrons. The latter has been typically identified as the modified two-stream instability. The diamagnetic-driven modes are found to be important in regions of the channel where ions begin to accelerate since υ E ∼ υ D e there. The theoretical model compares extremely well with a large set of empirical profiles of v e a derived from laser-induced fluorescence measurements. Our model validation comparisons spanned thrusters with >10× range in discharge power, various sizes and operating conditions, in unshielded and shielded magnetic field topologies. The kinetic version of our closed-form expression yields the scaling v e a ∼ ω c e υ T i e τ ¯ / (υ E + υ D e) , where τ ¯ ∼ ω L H / v i , v i is the sum of the ionization and charge-exchange frequencies and υ T i is the ion thermal speed. The latter must be determined by the appropriate integration of the ion velocity distribution function and include not only random changes of the drift velocity but also ion production. [ABSTRACT FROM AUTHOR]

Background: Active bone remodeling processes can be altered by the presence of reactive oxygen species and, therefore, cause leg problems in broiler chickens. The antioxidant activity present in grape seed extract (GSE) could be a viable alternative to high inclusion levels of vitamin E (VE) as a nutritional strategy to improve the antioxidant capacity of birds and, thus, prevent leg abnormalities. Objective: To evaluate the effect of partial substitution of VE with grape GSE on leg health and performance of broiler chickens. Methods: Four hundred and twenty newly-hatched Ross 308 male broiler chickens were distributed into three treatments: 1) Control-AL, a diet containing 40 IU/kg of VE and fed ad libitum (CAL); 2) Control-FR, the CAL diet but offered through a feed restriction program (CFR); and 3) grape seed extract-AL, a diet containing 10 mg/kg of GSE + 10 IU/kg of VE fed ad libitum (GSE-AL). The trial was conducted for 47 days. Feed intake and body weight of the chickens were recorded weekly to evaluate performance. At day 43, gait score (GS), valgus/varus angulation (AngV), foot burn (FB), and hock burn (HB) lesions were evaluated. At day 47, tibia-breaking strength (TBS) and gastrocnemius tendon-breaking strength (GTBS) were evaluated. Results: Birds in the GSE-AL treatment showed reduced (p=0.05) GS compared to the other treatments. No statistical differences (p>0.05) were found in AngV, HB, FB, TBS, TGBS, and growth performance among treatments. Conclusions: These results suggest that GSE may partially replace VE in broiler diets without negative effects on growth performance or leg health. Further research is required to evaluate the potential of grape seed extract to replace VE or other ingredients with antioxidant activity under different rearing conditions and feeding programs. [ABSTRACT FROM AUTHOR]

By using linking and ∇ -theorems in this paper we prove the existence of multiple solutions for the following nonlocal problem with mixed Dirichlet–Neumann boundary data, (− Δ) s u = λ u + f (x , u) in  Ω , u = 0 on  Σ , ∂ u ∂ ν = 0 on  Σ , where (− Δ) s , s ∈ (1 / 2 , 1) , is the spectral fractional Laplacian operator, Ω ⊂ ℝ N , N > 2 s , is a smooth bounded domain, λ > 0 is a real parameter, ν is the outward normal to ∂ Ω , Σ , Σ are smooth (N − 1) -dimensional submanifolds of ∂ Ω such that Σ ∪ Σ = ∂ Ω , Σ ∩ Σ = ∅ and Σ ∩ Σ ¯ = Γ is a smooth (N − 2) -dimensional submanifold of ∂ Ω. [ABSTRACT FROM AUTHOR]

Anisopteromalus calandrae (Howard) and Theocolax elegans (Westwood) have been recorded as parasitoids of the maize weevil, Sitophilus zeamais (Motschulsky), and were collected from maize (Zea mays L.) in the Huasteca Hidalguense. Both species of parasitoids are new records for Hidalgo, and to our knowledge, this is the first report of the association of T. elegans with S. zeamais in Mexico. [ABSTRACT FROM AUTHOR]

Se reporta por primera vez a Tromatobia sp. (Hymenoptera: Ichneumonidae) asociada con Neoscona oaxacensis (Araneae: Araneidae), araña que exhibe cuidados maternos prolongados de sus sacos de huevos u ovisacos, en Toluca, Estado de México. El ichneumónido infestó 24% de los ovisacos individuales. No se documentó la presencia de huevos del ichneumónido en los ovisacos infestados. Las larvas de Tromatobia sp. consumieron la totalidad de los huevos de N. oaxacensis y próximas a pupar construyeron cocones individuales, colocándolos uno al lado del otro. Por cada ovisaco individual infestado de N. oaxacensis se encontraron dos a tres pupas y/o adultos de Tromatobia sp. Los adultos abandonaron el interior de los cocones a través de orificios de 2 mm de diámetro. Este estudio representa la primera interacción trófica que ocurre entre Tromatobia sp. y la araña Neoscona oaxacensis en México. Tromatobia sp. (Hymenoptera: Ichneumonidae) is reported for the first time associated with Neoscona oaxacensis (Araneae: Araneidae), a spider that exhibits prolonged maternal care of its egg sacs or ovisacs, in Toluca, State of Mexico. The ichneumonid infested 24% of individual ovisacs. The presence of ichneumonid eggs was not documented in the infested ovisacs. Larvae of Tromatobia sp. consumed all the eggs of N. oaxacensis and, close to pupating, built individual cocoons, placing them side by side. For each individual ovisac infested of N. oaxacensis, two to three pupae and/or adults were counted. Adults left the interior of the cocoons through 2 mm diameter holes. This study represents the first trophic interaction occurring between Tromatobia sp. and N. oaxacensis in Mexico. [ABSTRACT FROM AUTHOR]

Cloud platforms are widely employed in today's educational context to quality of the teaching-learning process. In 2016, Nextcloud was implemented in the Faculty of Chemical Engineering at the Technological University of Havana «José Antonio Echeverría» (CUJAE), Cuba. Subsequently, an evaluative phase was conducted to ensure the continuous development of the platform. The objective was to assess the use and acceptance of the Nextcloud platform from the perspective of students and professors in the faculty. Data was collected through observation and a survey. Matomo Analytics tool was employed for observation, revealing low visitation numbers. The survey was based on the Unified Theory of Acceptance and Use of Technology model. It is concluded that the evaluation of the Nextcloud platform is infrequently used by users; however, there were better results were obtained in positive acceptances compared to negative ones, both for professors and students. [ABSTRACT FROM AUTHOR]

This study aims to investigate two key aspects in a mouse model of ocular hypertension (OHT): first, the time course of retinal ganglion cell (RGC) death and the parallel activation of caspase-3 (a-Casp3+ cells) to narrow the therapeutic window; and second, the effect of caspase-3 and microglia inhibition by minocycline on RGC rescue in this model. RGC loss after OHT induction was significant at day 7 and progressed to 30 days. However, anatomical RGC death was preceded by significant Casp3 activation on day 3. Microglial inhibition by minocycline did not alter the course of OHT or rescue RGCs but resulted in a decrease in a-Casp3+ cells and phagocytic and total microglia. Therefore, RGC death commitment occurs earlier than their loss of Brn3a expression, microglial cells do not exacerbate RGC loss, and while this death is primarily apoptotic, apoptosis inhibition does not rescue RGCs, suggesting that alternative death pathways play a role in glaucomatous injury.