2,366 research outputs found

    An Adaptive Dynamic Surface Controller for Ultralow Altitude Airdrop Flight Path Angle with Actuator Input Nonlinearity

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    In the process of ultralow altitude airdrop, many factors such as actuator input dead-zone, backlash, uncertain external atmospheric disturbance, and model unknown nonlinearity affect the precision of trajectory tracking. In response, a robust adaptive neural network dynamic surface controller is developed. As a result, the aircraft longitudinal dynamics with actuator input nonlinearity is derived; the unknown nonlinear model functions are approximated by means of the RBF neural network. Also, an adaption strategy is used to achieve robustness against model uncertainties. Finally, it has been proved that all the signals in the closed-loop system are bounded and the tracking error converges to a small residual set asymptotically. Simulation results demonstrate the perfect tracking performance and strong robustness of the proposed method, which is not only applicable to the actuator with input dead-zone but also suitable for the backlash nonlinearity. At the same time, it can effectively overcome the effects of dead-zone and the atmospheric disturbance on the system and ensure the fast track of the desired flight path angle instruction, which overthrows the assumption that system functions must be known

    Characterization of Electronic Cigarette Aerosol and Its Induction of Oxidative Stress Response in Oral Keratinocytes.

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    In this study, we have generated and characterized Electronic Cigarette (EC) aerosols using a combination of advanced technologies. In the gas phase, the particle number concentration (PNC) of EC aerosols was found to be positively correlated with puff duration whereas the PNC and size distribution may vary with different flavors and nicotine strength. In the liquid phase (water or cell culture media), the size of EC nanoparticles appeared to be significantly larger than those in the gas phase, which might be due to aggregation of nanoparticles in the liquid phase. By using in vitro high-throughput cytotoxicity assays, we have demonstrated that EC aerosols significantly decrease intracellular levels of glutathione in NHOKs in a dose-dependent fashion resulting in cytotoxicity. These findings suggest that EC aerosols cause cytotoxicity to oral epithelial cells in vitro, and the underlying molecular mechanisms may be or at least partially due to oxidative stress induced by toxic substances (e.g., nanoparticles and chemicals) present in EC aerosols

    ENU-Induced Mutagenesis in Grass Carp (Ctenopharyngodon idellus) by Treating Mature Sperm

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    N-ethyl-N-nitrosourea (ENU) mutagenesis is a useful approach for genetic improvement of plants, as well as for inducing functional mutants in animal models including mice and zebrafish. In the present study, mature sperm of grass carp (Ctenopharyngodon idellus) were treated with a range of ENU concentrations for 45 min, and then wild-type eggs were fertilized. The results indicated that the proportion of embryos with morphological abnormalities at segmentation stage or dead fry at hatching stage increased with increasing ENU dose up to 10 mM. Choosing a dose that was mutagenic, but provided adequate numbers of viable fry, an F1 population was generated from 1 mM ENU-treated sperm for screening purposes. The ENU-treated F1 population showed large variations in growth during the first year. A few bigger mutants with morphologically normal were generated, as compared to the controls. Analysis of DNA from 15 F1 ENU-treated individuals for mutations in partial coding regions of igf-2a, igf-2b, mstn-1, mstn-2, fst-1and fst-2 loci revealed that most ENU-treated point mutations were GC to AT or AT to GC substitution, which led to nonsense, nonsynonymous and synonymous mutations. The average mutation rate at the examined loci was 0.41%. These results indicate that ENU treatment of mature sperm can efficiently induce point mutations in grass carp, which is a potentially useful approach for genetic improvement of these fish

    Dietary inclusion of fermented ginger straw effect on the growth performance, gastrointestinal tract development and caecal fermentation of fattening rabbits

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    [EN] This experiment was conducted to evaluate the effects of dietary inclusion of fermented ginger straw on the growth performance, gastrointestinal tract development and caecal fermentation of fattening rabbits. A total of 160 45-d-old Laiwu black rabbits were randomly divided into 4 groups and fed 0% (Control), 5, 10 or 15% fermented ginger straw in their diet as a replacement for peanut straw powder. The trial lasted for 7 d of adaptation and 43 d for testing. Growth performance was recorded from 52 to 95 d of age (n=5 per treatment with 30 rabbits, 3 males and 3 females per replicate), TTAD of nutrients from 91 to 95 d of age, and gastrointestinal tract development, caecum fermentation and carcass traits were determined at 95 d of age (n=5 per treatment with 10 rabbits, 1 males and 1 females in per replicate).The results showed that the average daily gain and final body weight in the experimental groups (5, 10 and 15% fermented ginger straw) were higher than in the control group (P<0.05). However, the average daily feed intake in the 15% group was higher than in the other groups, while the total tract apparent digestibility of crude protein, ether extract, neutral detergent fibre and acid detergent fibre were lower than in the control group (P<0.05), and the relative weights of the stomach, small intestine and caecum content in the 15% substitution group were higher than those in the control group (P<0.05). In addition, the thickness of the muscle layer in the 15% substitution group was higher than that in the other groups (P<0.05). Moreover, pH and total volatile fatty acids concentration in the caecal content were similar among the 4 groups (P>0.05). The current work shows that fermented ginger straw could be used as roughage material in fattening rabbit production up to a dietary dose of 10%.This study was supported by Earmarked Fund for Modern Agro-industry Technology Research System (CARS-43-G-7); Shandong Province Modern Agricultural Industry Technology System (SDAIT-21); Scientific and Technological Problems Project Unveiled by Shandong Academy of Agricultural Sciences (SHJB2021-43).Sun, HT.; Wang, Y.; Bai, LY.; Liu, C.; Xu, YH.; Gao, SX.; Jiang, WX.... (2022). Dietary inclusion of fermented ginger straw effect on the growth performance, gastrointestinal tract development and caecal fermentation of fattening rabbits. World Rabbit Science. 30(4):267-276. https://doi.org/10.4995/wrs.2022.1609326727630

    Renal Protective Effect of Sirtuin 1

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    Silent information regulator 2 (Sir2) is a nicotinamide adenine dinucleotide-(NAD + -) dependent deacetylase. The homology of SIRT1 and Sir2 has been extensively studied. SIRT1 deacetylates target proteins using the coenzyme NAD + and is therefore linked to cellular energy metabolism and the redox state through multiple signalling and survival pathways. During the past decade, investigators have reported that SIRT1 activity is essential in cancer, neurodegenerative diseases, diabetes, cardiovascular disease, and other age-related diseases. In the kidneys, SIRT1 may inhibit renal cell apoptosis, inflammation, and fibrosis. Therefore its activation may also become a new therapeutic target in the patients with chronic kidney disease including diabetic nephropathy. In this paper, we would like to review the protective functions of sirtuins and the role of SIRT1 in the onset of kidney disease based on previous studies, including diabetic nephropathy, acute renal injury, chronic kidney disease as well as lupus nephritis

    Evaluation of the hepatotoxicity of Psoralea corylifolia L. based on a zebrafish model

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    Objective:Psoralea corylifolia L. (FP) has received increasing attention due to its potential hepatotoxicity.Methods: In this study, zebrafish were treated with different concentrations of an aqueous extract of FP (AEFP; 40, 50, or 60 μg/mL), and the hepatotoxic effects of tonicity were determined by the mortality rate, liver morphology, fluorescence area and intensity of the liver, biochemical indices, and pathological tissue staining. The mRNA expression of target genes in the bile acid metabolic signaling pathway and lipid metabolic pathway was detected by qPCR, and the mechanism of toxicity was initially investigated. AEFP (50 μg/mL) was administered in combination with FXR or a peroxisome proliferator-activated receptor α (PPARα) agonist/inhibitor to further define the target of toxicity.Results: Experiments on toxic effects showed that, compared with no treatment, AEFP administration resulted in liver atrophy, a smaller fluorescence area in the liver, and a lower fluorescence intensity (p < 0.05); alanine transaminase (ALT), aspartate transaminase (AST), and γ-GT levels were significantly elevated in zebrafish (p < 0.01), and TBA, TBIL, total cholesterol (TC), TG, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were elevated to different degrees (p < 0.05); and increased lipid droplets in the liver appeared as fatty deposits. Molecular biological validation revealed that AEFP inhibited the expression of the FXR gene, causing an increase in the expression of the downstream genes SHP, CYP7A1, CYP8B1, BSEP, MRP2, NTCP, peroxisome proliferator-activated receptor γ (PPARγ), ME-1, SCD-1, lipoprotein lipase (LPL), CPT-1, and CPT-2 and a decrease in the expression of PPARα (p < 0.05).Conclusion: This study demonstrated that tonic acid extracts are hepatotoxic to zebrafish through the inhibition of FXR and PPARα expression, thereby causing bile acid and lipid metabolism disorders

    Glomerular capillary C3 deposition as a risk factor for unfavorable renal outcome in pediatric primary focal segmental glomerular sclerosis

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    IntroductionSome patients with primary focal segmental sclerosis (FSGS) demonstrate complement 3 (C3) deposition in glomerular capillary loops (Cap-C3) and/or mesangial area (Mes-C3). The clinicopathological and prognostic significance of C3 deposition remains incompletely investigated, especially in the pediatric cohort.MethodsWe retrospectively analyzed 264 children of biopsy-proven primary FSGS between January 2003 and December 2020. The correlation between Cap-C3 and renal outcome was evaluated by the Kaplan-Meier method and Cox multivariate regression analysis. Renal end-point event was defined as the development of end-stage renal disease, death for renal disease, or an estimated glomerular filtration rate reduction by at least 50% from baseline.ResultsAmong the 264 patients, 30 (11.4%) had Cap-C3. Kaplan-Meier analysis showed that patients with Cap-C3 had significantly lower renal survival rates than patients without Cap-C3 (60.17% vs. 84.71% at 5 years, 39.49% vs. 65.55% at 10 years, P < 0.01). Cox multivariate regression analysis showed that Cap-C3 was an independent risk factor for poor renal outcome (HR 3.53, 95% CI 1.22–10.19, P = 0.02).ConclusionGlomerular capillary C3 deposition was an independent risk factor for unfavorable renal outcome in children with primary FSGS
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