RESUMO
The zebrafish (Danio rerio) is a valuable animal model rapidly becoming more commonly used in pharmaceutical studies. Due to its low-cost maintenance and high breeding potential, the zebrafish is a suitable substitute for most adult rodents (mice and rats) in neuroscience research. It is widely used in various anxiety models. This species has been used to develop a conceptual framework for anxiety behavior studies with broad applications in the laboratory, including the study of herbal and chemical drugs. This review discusses the latest studies of anxiety-related behavior in the zebrafish model.
Assuntos
Pesquisa Farmacêutica , Peixe-Zebra , Animais , Camundongos , Ratos , Modelos Animais de Doenças , Comportamento Animal , Ansiedade/tratamento farmacológicoRESUMO
We report the effect of the geometric parameters on transparency and conductivity in a metallic nanowire mesh as a transparent electrode. Today, indium tin oxide and fluorine-doped tin oxide are used as the transparent electrode for displays and solar cells. Still, there is a definite need for their replacement due to drawbacks such as brittleness, scarcity, and adverse environmental effects. Metallic nanowire mesh is likely the best replacement option, but the main issue is how to find the optimal structure and how to get the best performance. Since the interaction of light with nanowire mesh is complicated, there is no straightforward rule with a simple analytical solution. We developed a kit based on wave optics for calculating the optical transmission of metallic nanowire mesh, which, unlike previous works, includes the interaction of light with the nanowire mesh, such as localized surface plasmon resonance (LSPR), surface plasmon polariton (SPP), and Rayleigh anomaly (RA). So, it is possible to accurately predict the effect of these phenomena and the transmission of mesh. Using the mentioned kit, we will be able to investigate the different geometrical structures of meshes to achieve optimal geometry. This kit is based on the classical Maxwell theory and empirical data and uses finite-difference time-domain for solving equations and experiential results for validation. Comparing the results by a redefined figure of merit shows that LSPR has the most significant reduction on transparency, whereas increasing the thickness (t) to width (w) ratio of the nanowire in the metallic mesh can reduce the LSPR effect and/or shifts it to the invisible region. The wire pitch (p) has no tangible impact on LSPR, but p can be chosen higher than 700 or lower than 350 nm to remove the extinction effects of the first-order RA. If p was larger than 150 nm, SPP could appear in the visible region of the spectrum. In small p, lower modes of SPP with higher intensities occur; therefore, there is an optimum value for p around 300 nm. The reduction of t and w reduces the intensity of SPP and causes it to red shift. By comparing the 900 different structures, the highest figure of merit is obtained in a p of 300 nm with a minimum w (10 nm) and maximum t (100 nm).
RESUMO
Naturally, the presence of electromagnetic waves in our living environment affects all components of organisms, particularly humans and animals, as the large part of their body consists of water. In the present study, we tried to investigate the relation between exposure to the extremely low-frequency electromagnetic field (ELF-EMF) and common behaviors such as body weight, food and water intake, anorexia (poor appetite), plasma glucose concentration, movement, rearing and sniffing in rats. For this purpose, rats were exposed to 40 Hz ELF-EMF once a day for 21 days, then at days 1, 3, 7, 14 and 21 after exposure, any changes in the above-mentioned items were assessed in the exposed rats and compared to the non-exposed group as control. Body weight of irradiated rats significantly increased only a week after exposure and decreased after that. No significant change was observed in food and water intake of irradiated rats compared to the control, and the anorexia parameter in the group exposed to ELF-EMF was significantly decreased at one and two weeks after irradiation. A week after exposure, the level of glucose was significantly increased but at other days these changes were not significant. Movements, rearing and sniffing of rats at day 1 after exposure were significantly decreased and other days these changes did not follow any particular pattern. However, the result of this study demonstrated that exposure to ELF-EMF can alter the normal condition of animals and may represent a harmful impact on behavior.
Assuntos
Comportamento Animal/efeitos da radiação , Campos Eletromagnéticos/efeitos adversos , Animais , Anorexia/etiologia , Comportamento Animal/fisiologia , Peso Corporal/efeitos da radiação , Encéfalo/fisiologia , Encéfalo/efeitos da radiação , Ingestão de Líquidos/efeitos da radiação , Glucose/metabolismo , Masculino , Modelos Animais , Movimento/efeitos da radiação , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Parkinson's disease (PD) is one of the most frequent degenerative central nervous system disorders affecting older adults. Dopaminergic neuron failure in the substantia nigra is a pathological sign connected with the motor shortfall of PD. Due to their low teratogenic and adverse effect potential, medicinal herbs have emerged as a promising therapy option for preventing and curing PD and other neurodegenerative disorders. However, the mechanism through which natural compounds provide neuroprotection against PD remains unknown. While testing compounds in vertebrates such as mice is prohibitively expensive and time-consuming, zebrafish (Danio rerio) may offer an appealing alternative because they are vertebrates and share many of the same characteristics as humans. Zebrafish are commonly used as animal models for studying many human diseases, and their molecular history and bioimaging properties are appropriate for the study of PD. However, a literature review indicated that only six plants, including Alpinia oxyhylla, Bacopa monnieri, Canavalia gladiate, Centella asiatica, Paeonia suffruticosa, and Stachytarpheta indica had been investigated as potential PD treatments using the zebrafish model. Only C. asiatica and B. monnieri were found to have potential anti-PD activity. In addition to reviewing the current state of research in this field, these plants' putative mechanisms of action against PD are explored, and accessible assays for investigation are made.
Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Plantas Medicinais , Animais , Camundongos , Humanos , Idoso , Doença de Parkinson/tratamento farmacológico , Peixe-Zebra , Neurônios Dopaminérgicos , Modelos Animais de DoençasRESUMO
Time-dependent model is presented to simulate random lasers in the presence of an inhomogeneous gain medium. PbSe quantum dots (QDs) with an arbitrary size distribution are treated as an inhomogeneous gain medium. By introducing inhomogeneity of the PbSe QDs in polarization, rate, and Maxwell's equations, our model is constructed for a one-dimensional disordered system. By employing the finite difference time-domain method, the governing equations are numerically solved and lasing spectra and spatial distribution of the electric field are calculated. The effect of increasing the pumping rate on the laser characteristics is investigated. The results show that the number of lasing modes and their intensities increase with pumping rate. It is also demonstrated that the emission spectra depend on the standard deviation of the Gaussian distribution function. Increasing the standard deviation leads to reduction of the laser intensity.
RESUMO
Low-cost inorganic hole-transporting materials (HTMs) accompanied by a printable carbon electrode is an efficient approach to address the limitation of material cost of perovskite solar cells (PSCs) and get this technology closer to commercialization. The present work is focused on optimizing the Zn/Sn ratio of Cu2ZnSnS4/carbon hole collectors in n-i-p structured PSCs, where CuInS2/carbon is applied as the reference hole collector. This composition regulation is a solution to address the challenge of composition-related defects of the Cu2ZnSnS4 (CZTS) material. The Zn/Sn ratio was tuned by the initial proportion of the zinc precursor during the nanoparticle (NP) synthesis using a heating-up procedure. It was found that the enhancement of the Zn/Sn ratio leads to a gradual increase of the optical band gap. More importantly, an increased density of B-type defect clusters [2ZnCu + ZnSn] is confirmed using Raman results. Additionally, results from the cyclic voltammetry measurement show that by increasing the Zn/Sn value, the highest occupied molecular orbital (HOMO) of HTM is pulled down. These data match the upward trend of photovoltage. CZTS HTM with an optimal Zn/Sn ratio of 1.5 has a compatible energy level, along with the features of uniform and smooth coverage. The best efficiency of about 14.86% was obtained for optimal CZTS/carbon-based PSCs, which reaches from 14.86 to 15.49% after 25 days of aging.
RESUMO
Due to the favorable properties of two-dimensional materials such as SnS2, with an energy gap in the visible light spectrum, and InSe, with high electron mobility, the combination of them can create a novel platform for electronic and optical devices. Herein, we study a tunable gain SnS2/InSe Van der Waals heterostructure photodetector. SnS2 crystals were synthesized by chemical vapor transport method and characterized using X-ray diffraction and Raman spectroscopy. The exfoliated SnS2 and InSe layers were transferred on the substrate. This photodetector presents photoresponsivity from 14 mA/W up to 740 mA/W and detectivity from 2.2 × 108 Jones up to 3.35 × 109 Jones by gate modulation from 0 V to +70 V. Light absorption and the charge carrier generation mechanism were studied by the Silvaco TCAD software and the results were confirmed by our experimental observations. The rather high responsivity and visible spectrum response makes the SnS2/InSe heterojunction a potential candidate for commercial visible image sensors.
RESUMO
Introduction: The effects of short-term and long-term exposures to 2.45 GHz radiofrequency electromagnetic radiation (RF-EMR) on anxiety-like behavior, corticosterone level, and gene expression were investigated. The goal of this study was to explore the effect of electromagnetic fields of 2.45 GHz on clinical signs such as body weight and anxiety-like behavior, including the elevated plus maze test and open-field test, and also on messenger RNA (mRNA) expression of Bax (Bcl2-associated x) and Bcl-2 (B-cell lymphoma 2) genes on the cognitive memory functions in an animal model of rats. Methods: The animals were classified into eight groups, sham groups and exposed groups for short-term and long-term exposures to the same dose of RF-EMR for one hour daily. The Wi-Fi equipment in the sham control group was not turned on during the experiment. Both genes were further confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR). The semi-quantitative PCR method of electromagnetic fields in the 2.45 GHz range impacted the expression of Bax and Bcl-2 genes in the rat's memory. Results: The present study exhibited that short-term radiation could decrease the percentage of entry into the open arm and the percentage of time spent, while there were no substantial impacts on the long-term radiation effect. Our data support the hypothesis that short-term exposure worked as a systemic stressor, raising plasma corticosterone and changing glucocorticoid receptor expression in the hippocampus. Conclusion: Additional research on this specific frequency and amount of radiation is required to discover strategies for protecting the nervous system from the detrimental effects of RF-EMR radiation.
RESUMO
Introduction: Fear memories are influenced by psychological and environmental variables. We evaluated the effect of 2.45 GHz microwave radiation on rats' fear learning and memory ability to determine the potential risks. The present study aimed to assess the impacts of corticosterone (CORT) levels on the consolidation and reconsolidation of fear conditioning memories. Methods: The rats were evaluated in contextual fear conditioning using foot shocks in both short-term (7 days) exposure and long-term (30 days) exposure. Young male Wistar rats were continually exposed to radio frequency electromagnetic field radiation for 5-6 weeks (1 h/day) with a frequency, power density, and pulse width of 2.45 GHz, 6.0 mW/cm2, and 2 ms, respectively. Several animals housed in identical conditions without exposure to radiation were monitored. Results: Based on the results, a significant increase and decrease in body weight and percentage of the freezing time were observed after the short-term group respectively. However, in the long term, we observed no significant difference in body weight, and the freezing time decreased substantially. Conclusion: As CORT levels were analyzed, long-term radiation might increase stress, which was associated with significant weight loss in rats.
RESUMO
Introduction: In everyday life, electrical devices are the primary sources of extremely low-frequency electromagnetic fields (ELF-EMF), and the human body may be a great conductor of these fields. We chose alpha band power, especially at 10 Hz frequency, due to its prior beneficial role in memory. The purpose was to clarify whether there is a relationship between ELF-EMF exposure and cognitive deficits in rats, clinical signs, behavioral analysis, and the impact of ELF-EMF during different times of exposure on neuroplasticity via the expression of BDNF. Methods: Forty adult male rats were selected randomly. The rats were exposed to ELF-EMF (10 Hz, 4 mT) for 7 days and 30 days, one hour daily. The expression of BDNF proteins in the hippocampus was evaluated after sacrificing animals to assess learning and memory function. The body weight of rats in the long-term exposed group differed significantly (P<0.05). The level of BDNF mRNA in the hippocampus was found by the RT-PCR method. Results: Our findings indicate that exposure to ELF-EMF affects spatial learning and memory and can improve memory, especially with long-term exposure. In addition, we discovered a significant difference in the long-term exposed group (P<0.05), where radiation for 30 days resulted in a substantial rise in BDNF levels. Conclusion: After prolonged exposure, male rats spent more time and traveled a greater percentage of their distance in the target quadrant, demonstrating that long-term exposure improves spatial memory and that 10 Hz might be safe.
RESUMO
By making aligned and suspended copper nanowires, a high performance, transferable, and flexible transparent electrode is reported. Indium tin oxide is often used in devices such as displays, solar cells, and touchscreens that require transparent and conductive plates. Because of problems such as brittleness, high cost, and environmental effects, this material is facing rivals, the most serious of which are metallic nanowire meshes, especially copper. We developed a simple technique which uses a U-shaped collector in the electrospinning process with three advantages including the enhancement of the figure of merit (which is related to the surface resistance R s and the transmittance T) by about five times (about T = 90% and R s = 5 Ω/â¡, respectively), solving the transfer problem of the nanowire metal mesh after production, and producing aligned metal nanowires for special applications. In this work, T and R s of aligned copper nanowires were both measured and calculated, which are consistent with each other, and also, the mentioned results were compared with the work of others.
RESUMO
AIM: Since interactome analysis of diseases can provide candidate biomarker panel related to the diseases, in this research, protein-protein interaction (PPI) network analysis is used to introduce the involved crucial proteins in Gastric adenocarcinoma (GA). BACKGROUND: Gastric adenocarcinoma (GA) is the most common type of stomach cancer. There is no efficient diagnostic molecular method for GA. METHOD: Applying Cytoscape software 3.4.0 and String Database, the PPI network was constructed for 200 genes. Based on centrality parameters, the critical nodes were screened. Gene ontology of the key proteins for pathway analysis and molecular function processing were done and the highlighted pathways and activities were discussed. RESULTS: Among 200 initial genes, 141 genes were included in a main connected network. Seven crucial proteins, including tumor protein p53, epidermal growth factor receptor, albumin, v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog (avian), v-akt murine thymoma viral oncogene homolog 1, v-src sarcoma (Schmidt-Ruppin A-2) viral oncogene homolog (avian) and catenin (cadherin-associated protein), beta 1, 88kDa, and Myogenic differentiation 1, were introduced as key nodes of the network. These identified proteins are mostly involved in pathways and activities related to cancer. CONCLUSION: In conclusion, the finding is corresponding to the significant roles of these introduced proteins in GA disease. This protein panel may be a useful probe in the management of GA.
RESUMO
Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas nor-adrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure.