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1.
Channels (Austin) ; 18(1): 2313323, 2024 12.
Artigo em Inglês | MEDLINE | ID: mdl-38354101

RESUMO

The members of the superfamily of Transient Receptor Potential (TRP) ion channels are physiologically important molecules that have been studied for many years and are still being intensively researched. Among the vanilloid TRP subfamily, the TRPV4 ion channel is an interesting protein due to its involvement in several essential physiological processes and in the development of various diseases. As in other proteins, changes in its function that lead to the development of pathological states, have been closely associated with modification of its regulation by different molecules, but also by the appearance of mutations which affect the structure and gating of the channel. In the last few years, some structures for the TRPV4 channel have been solved. Due to the importance of this protein in physiology, here we discuss the recent progress in determining the structure of the TRPV4 channel, which has been achieved in three species of animals (Xenopus tropicalis, Mus musculus, and Homo sapiens), highlighting conserved features as well as key differences among them and emphasizing the binding sites for some ligands that play crucial roles in its regulation.


Assuntos
Canais de Cátion TRPV , Canais de Potencial de Receptor Transitório , Camundongos , Animais , Canais de Cátion TRPV/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Mutação , Xenopus/metabolismo , Sítios de Ligação
2.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37534977

RESUMO

Generating pairs of Raman beams for gravimetry with fiber phase modulators is quite convenient but generates additional frequencies that must be filtered. The frequency filtering could be achieved by using a long (dispersive) birefringent calcite crystal followed by a polarizer that blocks the transmission of certain laser frequencies, as has been shown before. Here, we present a method to tune such a filter to the desired frequency position. The correction signal for the feedback is obtained by comparing (subtracting) the transmission through the filter when sending light that has been phase modulated or not, taking advantage of the fiber modulator that is already installed in the system. The method allows for continuously alternating between using the modulator for monitoring the filter position and other uses, an important characteristic for the operation of a complete gravimetric sequence.

3.
Micromachines (Basel) ; 13(11)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36363850

RESUMO

A solar cell structure with a graded bandgap absorber layer based on InGaN has been proposed to overcome early predicted efficiency. Technological issues such as carrier concentration in the p- and n-type are based on the data available in the literature. The influence of carrier concentration-dependent mobility on the absorber layer has been studied, obtaining considerable improvements in efficiency and photocurrent density. Efficiency over the tandem solar cell theoretical limit has been reached. A current density of 52.95 mA/cm2, with an efficiency of over 85%, is determined for a PiN structure with an InGaN step-graded bandgap absorption layer and 65.44% of power conversion efficiency for the same structure considering piezoelectric polarization of fully-strained layers and interfaces with electron and hole surface recombination velocities of 10-3 cm/s.

4.
PLoS One ; 17(3): e0264987, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35263358

RESUMO

Bryophyllum pinnatum (Lam.) Oken (BP) is a plant that is used worldwide to treat inflammation, infections, anxiety, restlessness, and sleep disorders. While it is known that BP leaves are rich in flavonoids, the extent of the beneficial and toxic effects of its crude extracts remains unclear. Although some neurobehavioral studies using leaf extracts have been conducted, none has examined the effects of water-extracted leaf samples. The zebrafish is a powerful animal model used to gain insights into the efficacy and toxicity profiles of this plant due to its high fecundity, external development, and ease of performing behavioral assays. In this study, we performed behavioral testing after acute exposure to different concentrations of aqueous extract from leaves of B. pinnatum (LABP) on larval zebrafish, investigating light/dark preference, thigmotaxis, and locomotor activity parameters under both normal and stressed conditions. LABP demonstrated dose-and time-dependent biphasic effects on larval behavior. Acute exposure (25 min) to 500 mg/L LABP resulted in decreased locomotor activity. Exposure to 300 mg/L LABP during the sleep cycle decreased dark avoidance and thigmotaxis while increasing swimming velocity. After sleep deprivation, the group treated with 100 mg/L LABP showed decreased dark avoidance and increased velocity. After a heating stressor, the 30 mg/L and 300 mg/L LABP-treated groups showed decreased dark avoidance. These results suggest both anxiolytic and psychoactive effects of LABP in a dose-dependent manner in a larval zebrafish model. These findings provide a better understanding of the mechanisms underlying relevant behavioral effects, consequently supporting the safe and effective use of LABP for the treatment of mood disorders.


Assuntos
Kalanchoe , Animais , Antioxidantes/farmacologia , Flavonoides , Extratos Vegetais/farmacologia , Folhas de Planta , Peixe-Zebra
5.
Toxics ; 9(12)2021 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-34941782

RESUMO

Manganese (Mn) is an important element; yet acute and/or chronic exposure to this metal has been linked to neurotoxicity and neurodegenerative illnesses such as Parkinson's disease and others via an unknown mechanism. To better understand it, we exposed a human neuroblastoma cell model (SH-SY5Y) to two Mn chemical species, MnCl2 and Citrate of Mn(II) (0-2000 µM), followed by a cell viability assay, transcriptomics, and bioinformatics. Even though these cells have been chemically and genetically modified, which may limit the significance of our findings, we discovered that by using RA-differentiated cells instead of undifferentiated SH-SY5Y cell line, both chemical species induce a similar toxicity, potentially governed by disruption of protein metabolism, with some differences. The MnCl2 altered amino acid metabolism, which affects RNA metabolism and protein synthesis. Citrate of Mn(II), however, inhibited the E3 ubiquitin ligases-target protein degradation pathway, which can lead to the buildup of damaged/unfolded proteins, consistent with histone modification. Finally, we discovered that Mn(II)-induced cytotoxicity in RA-SH-SY5Y cells shared 84 percent of the pathways involved in neurodegenerative diseases.

6.
Rev. cuba. ortop. traumatol ; 35(2): e405, 2021. ilus, tab
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1341472

RESUMO

Introducción: Las fracturas abiertas de tibia son un subconjunto de la carga de traumatismos en América Latina. Se examinaron cuestiones relacionadas con el tratamiento potencialmente críticas en Cuba, país con recursos limitados, pero con un programa nacional de salud estandarizado, coherencia en educación y similitudes de programas de posgrado. Objetivos: Describir los patrones de tratamiento de la fractura abierta de tibia en Cuba, y comparar las características del manejo agudo y tardío en siete provincias del país. Métodos: Se encuestaron 67 cirujanos ortopédicos para evaluar cuatro aspectos en el tratamiento de la fractura abierta: profilaxis antibiótica, irrigación y desbridamiento, estabilización y tratamiento de heridas. Se utilizó el método de muestreo por conveniencia para identificar a los cirujanos y el análisis se realizó mediante la prueba exacta de Fisher (p < 0,05). Resultados: Se administraron antibióticos posoperatorios durante más de 72 horas para las fracturas GA-I/II (49 por ciento) y las fracturas GA-III (70 por ciento). Los cirujanos de La Habana (n= 32) utilizaron con más frecuencia la fijación interna primaria para las fracturas GA-I/II, que los cirujanos en las restantes provincias (n= 35) (64,3 porciento vs. 30,3 por ciento, p= 0,008). Los cirujanos de otras provincias realizaron cierre primario en el momento de la fijación definitiva de fracturas GA-I /II con más frecuencia que los de La Habana (62,9 por ciento vs. 32,3 por ciento, p= 0,013). Para fracturas GA-III, la mayoría de los cirujanos habaneros (88,6 %), al igual que los de las restantes provincias (96,8 por ciento) prefirieron realizar cierre diferido.Conclusiones: El tratamiento de fracturas abiertas de tibia en Cuba es generalmente consistente con otros países de América Latina. Se describen las características del manejo de fracturas abiertas de tibia en Cuba y se comparan las diferencias en los métodos de estabilización y tratamiento de heridas entre provincias, lo cual resulta útil para evaluar si son resultado de diferencias en la práctica quirúrgica, o en la disponibilidad de recursos. Esto representa una ayuda al abordar las formas de optimizar la atención al paciente, a través de la capacitación especializada y la asignación de los recursos(AU)


Introduction: Open tibia fractures are a significant subset of the overall trauma burden in Latin America. Latin American countries vary in their access to orthopaedic care resources, and country-specific orthopaedic recommendations are necessary. Cuba, a country with limited resources, has a standardized national health program, consistencies in education, and similarities across post-graduate training programs. This study aimed to identify management preferences for open tibia factures in Cuba. Objectives: To describe the treatment of open tibial fractures in Cuba, and to compare the characteristics of acute and delayed management across seven Cuban provinces. Methods: Sixty-seven orthopaedic surgeons were surveyed to evaluate four aspects of open fracture management, regarding antibiotic prophylaxis, irrigation and debridement, stabilization, and wound management. The convenience sampling method was used to identify surgeons and the analysis was performed using Fisher's exact test (p <0.05). Results: Postoperative antibiotics were administered for more than 72 hours for GA-I / II fractures (49 pecent) and GA-III fractures (70 percent). Surgeons in Havana (n = 32) used primary internal fixation for GA-I / II fractures more frequently than surgeons in the remaining provinces (n = 35) (64.3 pecent vs. 30.3 percent p = 0.008). Surgeons from other provinces performed primary closure at the time of definitive fixation of GA-I / II fractures more frequently than those from Havana (62.9 percent vs. 32.3 percent, p = 0.013). For GA-III fractures, the majority of Havana surgeons (88.6 percent), as well as those of the remaining provinces (96.8 percent) preferred to perform deferred closure. Conclusions: The treatment of open tibial fractures in Cuba is generally consistent with other Latin American countries. The characteristics of the management of open tibial fractures in Cuba are described and differences in wound stabilization and treatment methods between provinces are compared, which is useful to assess whether they are the result of differences in surgical practice, or in availability of resources. This is helpful in addressing ways to optimize patient care through specialized training and resource allocation(AU)


Assuntos
Humanos , Masculino , Feminino , Fraturas da Tíbia , Diáfises/lesões , Fraturas Expostas
7.
Soft Matter ; 17(11): 3250-3253, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33704329

RESUMO

Correction for 'Collective motion of chiral Brownian particles controlled by a circularly-polarized laser beam' by Raúl Josué Hernández et al., Soft Matter, 2020, 16, 7704-7714, DOI: .

8.
Metallomics ; 12(11): 1656-1678, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33206086

RESUMO

Manganese (Mn) is essential for living organisms, playing an important role in nervous system function. Nevertheless, chronic and/or acute exposure to this metal, especially during early life stages, can lead to neurotoxicity and dementia by unclear mechanisms. Thus, based on previous works of our group with yeast and zebrafish, we hypothesized that the mechanisms mediating manganese-induced neurotoxicity can be associated with the alteration of protein metabolism. These mechanisms may also depend on the chemical speciation of manganese. Therefore, the current study aimed at investigating the mechanisms mediating the toxic effects of manganese in primary cultures of cerebellar granule neurons (CGNs). By exposing cultured CGNs to different chemical species of manganese ([[2-[(dithiocarboxy)amino]ethyl]carbamodithioato]](2-)-kS,kS']manganese, named maneb (MB), and [[1,2-ethanediylbis[carbamodithioato]](2-)]manganese mixture with [[1,2-ethanediylbis[carbamodithioato]](2-)]zinc, named mancozeb (MZ), and manganese chloride (MnCl2)), and using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, we observed that both MB and MZ induced similar cytotoxicity (LC50∼ 7-9 µM), which was higher than that of MnCl2 (LC50∼ 27 µM). Subsequently, we applied systems biology approaches, including metallomics, proteomics, gene expression and bioinformatics, and revealed that independent of chemical speciation, for non-cytotoxic concentrations (0.3-3 µM), Mn-induced neurotoxicity in CGNs is associated with metal dyshomeostasis and impaired protein metabolism. In this way, we verified that MB induced more post-translational alterations than MnCl2, which can be a plausible explanation for cytotoxic differences between both chemical species. The metabolism of proteins is one of the most energy consuming cellular processes and its impairment appears to be a key event of some cellular stress processes reported separately in other studies such as cell cycle arrest, energy impairment, cell signaling, excitotoxicity, immune response, potential protein accumulation and apoptosis. Interestingly, we verified that Mn-induced neurotoxicity shares pathways associated with the development of Alzheimer's disease, Amyotrophic Lateral Sclerosis, Huntington's disease, and Parkinson's disease. This has been observed in baker's yeast and zebrafish suggesting that the mode of action of Mn may be evolutionarily conserved.


Assuntos
Cerebelo/patologia , Manganês/toxicidade , Doenças Neurodegenerativas/patologia , Neurônios/patologia , Neurotoxinas/toxicidade , Animais , Morte Celular/efeitos dos fármacos , Cobre/metabolismo , Grânulos Citoplasmáticos/metabolismo , Homeostase/efeitos dos fármacos , Ferro/metabolismo , Camundongos , Neurônios/efeitos dos fármacos , Praguicidas/toxicidade , Potássio/metabolismo , Proteoma/metabolismo , Proteômica
9.
Soft Matter ; 16(33): 7704-7714, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32734983

RESUMO

We demonstrate the emergence of circular collective motion in a system of spherical light-propelled Brownian particles. Light-propulsion occurs as consequence of the coupling between the chirality of polymeric particles - left (L)- or right (R)-type - and the circularly-polarized light that irradiates them. Irradiation with light that has the same helicity as the particle material leads to a circular cooperative vortical motion between the chiral Brownian particles. In contrast, opposite circular-polarization does not induce such coupling among the particles but only affects their Brownian motion. The mean angular momentum of each particle has a value and sign that distinguishes between chiral activity dynamics and typical Brownian motion. These outcomes have relevant implications for chiral separation technologies and provide new strategies for optical torque tunability in mesoscopic optical array systems, micro- and nanofabrication of light-activated engines with selective control and collective motion.

10.
Int J Mol Sci ; 21(11)2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32481620

RESUMO

Transient Receptor Potential (TRP) channels are a family of ion channels whose members are distributed among all kinds of animals, from invertebrates to vertebrates. The importance of these molecules is exemplified by the variety of physiological roles they play. Perhaps, the most extensively studied member of this family is the TRPV1 ion channel; nonetheless, the activity of TRPV4 has been associated to several physio and pathophysiological processes, and its dysfunction can lead to severe consequences. Several lines of evidence derived from animal models and even clinical trials in humans highlight TRPV4 as a therapeutic target and as a protein that will receive even more attention in the near future, as will be reviewed here.


Assuntos
Canais de Cátion TRPV/fisiologia , Animais , Cálcio/metabolismo , Bovinos , Endotélio Vascular/metabolismo , Humanos , Rim/metabolismo , Camundongos , Microcirculação , Dor/metabolismo , Permeabilidade , Prognóstico , Domínios Proteicos , Ratos , Vasos Retinianos , Pele/metabolismo
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