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Insect visual electrophysiological techniques are important to study the electrical characteristics of photoreceptor cells and visual neurons in insects, including electroretinography (ERG) and microelectrode intracellular recording (MIR). ERG records the changes of voltage or electric current in the retina of insects in response to different light stimuli, which occurs outside the cell. MIR records the changes in individual photoreceptor cells or visual neurons of an insect exposed to different lights, which occurs inside the cell. Insect visual electrophysiological techniques can explore the mechanism of electrophysiological response of insects' vision to light and reveal their sensitive light spectra and photoreceptor types. This review introduced the basic structure and the principle of ERG and MIR, and summarized their applications in insect researches in the past 20 years, which would provide references for elucidating the mechanism of light perception in insects and the use of insect phototropism to control pests.
Assuntos
Eletrorretinografia , Insetos , Células Fotorreceptoras de Invertebrados , Animais , Insetos/fisiologia , Eletrorretinografia/métodos , Células Fotorreceptoras de Invertebrados/fisiologia , Visão Ocular/fisiologia , Microeletrodos , Fenômenos Eletrofisiológicos , Eletrofisiologia/métodosRESUMO
The rapid and low-cost preparation of powder activated coke (PAC) is very important for the promotion of fluidized dry desulfurization technology of activated coke. In order to explore the effect of rapid pyrolysis process on SO2 adsorption capacity of PAC, the fractal analysis of PAC prepared under different atmospheres was carried out. The Frenkel-Halsey-Hill (FHH) method was used to determine two fractal dimensions D1 and D2, under relative pressures of 0-0.5 and 0.5-1, respectively. The results indicate that the fractal dimensions were influenced by the concentrations of activation agents with D1 ranging from 2.1838 to 2.8643 and D2 ranging from 2.7485 to 2.9257. The effect of steam on the fractal dimension of PAC sample is small, but oxygen has a great promotion effect on the fractal dimension. An n-shaped curve-based relationship between fractal dimensions and coke yields is observed with a peak values of fractal dimensions appearing around 64% yield. The SO2 adsorption capacity shows a consecutively positive linear correlation with D2, while it illustrates distinctly different linear rates with D1 in intervals of 2-2.6 and 2.6-3, respectively. Taking advantage of fractal analysis as research method, this paper clarified the influence of activation atmosphere and ablative degree on the SO2 adsorption capacity of PAC, and the research conclusion provided a basis for the PAC preparation with high SO2 capacity.
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Microglia-mediated neuroinflammation is recognized to mainly contribute to the progression of neurodegenerative diseases. Epigallocatechin-3-gallate (EGCG), known as a natural antioxidant in green tea, can inhibit microglia-mediated inflammation and protect neurons but has disadvantages such as high instability and low bioavailability. We developed an EGCG liposomal formulation to improve its bioavailability and evaluated the neuroprotective activity in in vitro and in vivo neuroinflammation models. EGCG-loaded liposomes have been prepared from phosphatidylcholine (PC) or phosphatidylserine (PS) coated with or without vitamin E (VE) by hydration and membrane extrusion method. The anti-inflammatory effect has been evaluated against lipopolysaccharide (LPS)-induced BV-2 microglial cells activation and the inflammation in the substantia nigra of Sprague Dawley rats. In the cellular inflammation model, murine BV-2 microglial cells changed their morphology from normal spheroid to activated spindle shape after 24 h of induction of LPS. In the in vitro free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, EGCG scavenged 80% of DPPH within 3 min. EGCG-loaded liposomes could be phagocytized by BV-2 cells after 1 h of cell culture from cell uptake experiments. EGCG-loaded liposomes improved the production of BV-2 microglia-derived nitric oxide and TNF-α following LPS. In the in vivo Parkinsonian syndrome rat model, simultaneous intra-nigral injection of EGCG-loaded liposomes attenuated LPS-induced pro-inflammatory cytokines and restored motor impairment. We demonstrated that EGCG-loaded liposomes exert a neuroprotective effect by modulating microglia activation. EGCG extracted from green tea and loaded liposomes could be a valuable candidate for disease-modifying therapy for Parkinson's disease (PD).
Assuntos
Anti-Inflamatórios/farmacologia , Catequina/análogos & derivados , Microglia/patologia , Neuroproteção/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Biomarcadores/metabolismo , Catequina/farmacologia , Linhagem Celular , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Lipopolissacarídeos/farmacologia , Lipossomos , Camundongos , Microglia/efeitos dos fármacos , Óxido Nítrico/metabolismoRESUMO
Microwave-assisted methane reforming with carbon dioxide was dealt with in this work, using a Fe-rich biomass-derived char by one-step preparation. The main factors on the reforming reaction and stability of this catalyst were evaluated, together with a series of characterization on the produced gas and the used char. The char obtained from biomass pyrolysis with Fe2O3 addition of 10% exhibited the best performance on dry reforming reaction. A target CH4 conversion of 95% over this char was realized at 800⯰C. Moreover, H2/CO ratio achieved with this char was prone to approach the stoichiometric value. Compared to CO2 conversion, CH4 conversion was more promoted with the increase of CO2/CH4 ratio. The variation of CO2/CH4 ratio also leaded to a noticeable changes on H2/CO ratio. More importantly, the selected char presented a satisfied stability, evidenced by the total decrease of 4.8% for CH4 conversion and 3.1% for CO2 conversion in the test of 160â¯min. This was contributed to a depressed in-situ carbon consumption and a moderate deterioration of porous structure. Gaseous products obtained with the appropriate char in a long run had a syngas content of 88.79% and H2/CO ratio of 0.92 on average.
Assuntos
Carvão Vegetal/química , Ferro/química , Metano/química , Micro-Ondas , Energia Renovável , Animais , CatáliseRESUMO
The aim of this study is to examine the role of thioredoxin-2 (Trx2) in autophagy and apoptosis during myocardial ischemia-reperfusion (I/R) injury in vitro. We employed the oxygen-glucose deprivation and reperfusion (OGD/R) model of H9c2 cells and used lentiviral infection to overexpress Trx2. H9c2 cell viability and injury assays were conducted using a Cell Counting Kit-8 (CCK-8) and alactate dehydrogenase (LDH) kit. The effects of Trx2 on autophagy and apoptosis were measured by transmission electron microscopy (TEM), western blot, and flow cytometry. Our results showed that the expression of Trx2 was significantly decreased at reperfusion 6 h after OGD 12 h treatment. Trx2 overexpression inhibited autophagy in H9c2 cells subjected to OGD/R. As the underlying mechanisms, both Akt kinase/the mammalian target of rapamycin (Akt/mTOR) and AMP-activated protein kinase (AMPK)/mTOR signaling pathways were involved in the regulation of Trx2 during autophagy, which was also mediated by reactive oxygen species (ROS). 3-methyladenine (3-MA), an inhibitor of autophagy, not only suppressed OGD/R-induced autophagy but also decreased apoptosis. As a classical autophagy sensitizer, rapamycin (Rapa) augmented autophagy as well as apoptosis. Additionally, we further demonstrated that Trx2 could alleviate OGD/R-induced apoptosis via mitochondrion-mediated intrinsic apoptotic pathway. In summary, our data indicated that Trx2 protects cardiomyocytes under OGD/R by inhibiting autophagy and apoptosis. Trx2 may be a crucial regulatory protein during I/R-induced cardiomyocyte injury and death.
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OBJECTIVE: To explore the effect of okra extract on gestational diabetes mellitus (GDM) rats and its probable molecular mechanism. METHODS: A total of 30 female SD rats were caged with male rats for pregnancy, 27 pregnant rats were obtained and weighed. The pregnant rats were equally randomized into the control group, GDM group and intervention group. Once the pregnancy was verified, GDM group and intervention group were given 45 mg/kg streptozotocin by peritoneal injection for inducing GDM, control group was given equal volume of citrate buffer. Once the model was established successfully, intervention group was administered orally the solution containing 200 mg/kg/d okra extract, the other groups were given the diet and water only. On the 19th day of pregnancy, the blood samples and fetal rats of all groups were collected, fetal rats weight and placental weight was recorded and the serum glucose, lipids, serum insulin and C-peptide of pregnant rats before the delivery were determined. RESULTS: The pregnant rats weight before the delivery, fetal rats weight and placental weight of GDM group were lower than control group and intervention group (P < 0.05). After the treatment of okra extract, serum glucose and lipids levels of intervention group were both improved significantly (P < 0.05), especially, the FBG, HDL, FINS, serum m insulin and hepatic glycogen levels were equivalent to control group (P > 0.05). Antioxidant enzymes levels of GDM group in liver and pancreas tissues were lower than the other groups, and after treatment of okra extract, antioxidant enzymes levels in liver and pancreas tissues were equivalent to control group (P > 0.05). CONCLUSIONS: Okra extract, rich in antioxidant substances, could avoid the excessive consuming of antioxidant enzymes, then, suppresses the oxidative stress and insulin resistance, thereby improving blood glucose level of GDM rats.
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OBJECTIVE@#To explore the effect of okra extract on gestational diabetes mellitus (GDM) rats and its probable molecular mechanism.@*METHODS@#A total of 30 female SD rats were caged with male rats for pregnancy, 27 pregnant rats were obtained and weighed. The pregnant rats were equally randomized into the control group, GDM group and intervention group. Once the pregnancy was verified, GDM group and intervention group were given 45 mg/kg streptozotocin by peritoneal injection for inducing GDM, control group was given equal volume of citrate buffer. Once the model was established successfully, intervention group was administered orally the solution containing 200 mg/kg/d okra extract, the other groups were given the diet and water only. On the 19th day of pregnancy, the blood samples and fetal rats of all groups were collected, fetal rats weight and placental weight was recorded and the serum glucose, lipids, serum insulin and C-peptide of pregnant rats before the delivery were determined.@*RESULTS@#The pregnant rats weight before the delivery, fetal rats weight and placental weight of GDM group were lower than control group and intervention group (P 0.05). Antioxidant enzymes levels of GDM group in liver and pancreas tissues were lower than the other groups, and after treatment of okra extract, antioxidant enzymes levels in liver and pancreas tissues were equivalent to control group (P > 0.05).@*CONCLUSIONS@#Okra extract, rich in antioxidant substances, could avoid the excessive consuming of antioxidant enzymes, then, suppresses the oxidative stress and insulin resistance, thereby improving blood glucose level of GDM rats.
RESUMO
Objective: To explore the effect of okra extract on gestational diabetes mellitus (GDM) rats and its probable molecular mechanism. Methods: A total of 30 female SD rats were caged with male rats for pregnancy, 27 pregnant rats were obtained and weighed. The pregnant rats were equally randomized into the control group, GDM group and intervention group. Once the pregnancy was verified, GDM group and intervention group were given 45 mg/kg streptozotocin by peritoneal injection for inducing GDM, control group was given equal volume of citrate buffer. Once the model was established successfully, intervention group was administered orally the solution containing 200 mg/kg/d okra extract, the other groups were given the diet and water only. On the 19th day of pregnancy, the blood samples and fetal rats of all groups were collected, fetal rats weight and placental weight was recorded and the serum glucose, lipids, serum insulin and C-peptide of pregnant rats before the delivery were determined. Results: The pregnant rats weight before the delivery, fetal rats weight and placental weight of GDM group were lower than control group and intervention group (P 0.05). Antioxidant enzymes levels of GDM group in liver and pancreas tissues were lower than the other groups, and after treatment of okra extract, antioxidant enzymes levels in liver and pancreas tissues were equivalent to control group (P > 0.05). Conclusions: Okra extract, rich in antioxidant substances, could avoid the excessive consuming of antioxidant enzymes, then, suppresses the oxidative stress and insulin resistance, thereby improving blood glucose level of GDM rats.
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There is increasing evidence that natural killer (NK) cells play an important role in antitumor immunity following dendritic cell (DC) vaccination. Little is known, however, about the optimal stimulation of DCs by epitopes and NK interactions for cytotoxicity in tumors. In this study, DC cells activated by the HPV16E7.49-57 epitope and LPS were co-cultured with NK cells in vitro, and then used ot immunize mice to study CTL activity of TC-1, which constitutively expresses HPV16E6E7, with an LDH release assay. Cytotoxicity in mice immunized with DC loaded with epitope HPVE7.49-57 vaccine co-cultured with NK was enhanced significantly (p<0.01). In conclusion, talk-across between DC and NK cells enhances their functions, also improving cytotoxicity againsttumor cells, suggesting that activated DC-NK by epitopes has potential application for cancer-specific immuno-cellular therapy.