Comparison study of antibacterial properties of curcumin from Curcuma longa and enrofloxacin against Aeromonas hydrophila

Antibacterial properties of curcumin from turmeric (Curcuma longa) and enrofloxacin against Aeromonas hydrophila were assayed. The minimum inhibitory concentration (MIC) values of curcumin and enrofloxacin against A. hydrophila were found to be 100ug/ml and 9.375ug/ml, respectively. To realize the mechanisms of action of curcumin against A. hydrophila, we researched the antibacterial activity and bacterial membrane permeability of A. hydrophila cells treated with curcumin or enrofloxacin. All results elucidated that curcumin increased membrane permeabilization and caused leakage of intracellular contents, while its role was not as good as enrofloxacin. Moreover, a synergistic effect was shown between curcumin and enrofloxacin. The present study suggests that curcumin extracted from turmeric has the potential to be used as an antimicrobial for the control of A. hydrophila

A droplet-based triboelectric-piezoelectric hybridized nanogenerator for scavenging mechanical energy

Water droplet energy has received much attention as a newborn renewable energy source. Triboelectric nano -generators (TENGs) demonstrates enormous application in scavenging mechanical energy. Nowadays, the water droplet nanogenerator based on liquid-solid TENG has been greatly improved. However, these water droplet nanogenerators scavenge the mechanical energy of liquid-solid contact of water droplets by TENG, but not the deformation energy of the substrate. Here, we propose a new design strategy to increase the current of the water droplet nanogenerator through simultaneous scavenging of the mechanical energy of the liquid-solid contact and the deformation energy. A droplet-based triboelectric-piezoelectric hybridized nanogenerator (TPiHNG) with cantilever beam structure was fabricated under the strategy. The TPiHNG has a significantly higher current compared to TENG. The response time difference between piezoelectric nanogenerator (PiENG) and TENG is proposed for the first time as an important parameter of TPiHNG. This work provides a novel approach to scavenge water droplet energy more efficiently

Laser Irradiation on Limestone and Cracking: An Experimental Approach

Using mechanical drilling to obtain energy resources stored in deep and hard rock layers is becoming increasingly challenging. Therefore, laser irradiation has emerged as a new and promising drilling method. In this study, the effects of immersion conditions on rock-breaking by laser irradiation on the temperature, hole size, rock-breaking efficiency, and macro-fracture after laser irradiation were investigated. Furthermore, the mineral changes and thermogravimetric analysis of rocks were studied. As indicated by the results, the temperature area over 100 °C increases with the increase of irradiation time, and the temperature range of between 2.27 cm2 and 13.20 cm2 varies with the change of laser power at between 90 W and 135 W. The hole-diameter value of the soaked sample was smaller than that of the dried sample. In addition, the hole depth of the soaked sample reduced by 15% at a power of 90 W and 45% at a power of 135 W, compared with that of the dried sample. The value of the modified specific energy of the soaked sample increased, which was particularly noticeable at low power. The soaked sample had a larger effect on the rate of perforation at high power and a smaller effect at low power. The cracks on the surface of the rock samples became larger after being placed for one month. Fracture length increased from 0.61 to 5.09 mm for dried samples and from 2.24 to 8.7 mm for soaked samples at a laser power of 90 W. Fracture length increased from 6.30 to 9.85 mm for dried samples and from 9.04 to 11.38 mm for soaked samples at a laser power of 135 W. The soaked sample began to show differences when heated at 100 °C, which was caused by the evaporation of some free water molecules in the rock. The main weight loss temperatures of the samples occurred in the range of 640 °C to 900 °C

Dietary stachyose altered the intestinal microbiota profile and improved the intestinal mucosal barrier function of juvenile turbot, Scophthalmus maximus L.

Recent studies have revealed the beneficial effects of stachyose on intestinal histology and digestive function of fish. However, a comprehensive understanding of stachyose&#39;s impact on intestinal health of fish remains unclear, limiting its use in aqua-feed. In the present study, a 12-week feeding trial was conducted to investigate the effects of dietary stachyose on intestinal microbiota and mucosal barrier function of turbot (S. maximus L). Three isonitrogenous and isolipidic experimental diets were formulated to contain 0%, 1.25% and 5% stachyose, respectively. Sequencing of bacterial 16s rRNA V-4 region indicated that dietary stachyose altered the intestinal adherent microbiota profile, which was supported by the diet-cluster of PCA, PCoA, beta diversity heatmap and phylogenetic tree. LEfSe and MetaStat analysis indicated that both 1.25% and 5% dietary stachyose significantly elevated the abundance of intestinal cellulose-degrading bacteria. However, the higher level of stachyose (5%) increased the abundance of intestinal beneficial bacteria as well as that of potential pathogenic bacteria. Moreover, 1.25% dietary stachyose significantly up-regulated the genes expression of occludin, claudin-3, and ZO-1, and down-regulated the gene expression of claudin-like in the intestine (P&lt;0.05). Dietary stachyose at 5% significantly increased mucin-2 secretion and the gene expression of ZO-1, while significantly decreased the gene expression of claudin-like in the intestine (P&lt;0.05). Collectively, our study showed that dietary stachyose supplementation could favorably modulate the profile of intestinal microbiota and enhance the intestinal mucosal barrier function in juvenile turbot. Stachyose showed promising potential of being used as prebiotic in diet for enhancing the intestinal health of turbot.</p

The protective role of glutamine on enteropathy induced by high dose of soybean meal in turbot, Scophthalmus maximus L.

The aim of this study is to investigate the protective effect and regulatory mechanism of Gln on the enteropathy of turbot induced by soybean meal. Three isonitrogenous and isolipidic practical diets were formulated with fish meal basis (FM), soy protein replacing 40% fish meal protein (SBM) and dietary 2% Ala-Gln in SBM (Ala-Gin) for sextuple replicates of 30 fish each tank for 12 weeks. The fish in SBM group presented distinct enteropathy including declined absorptive surface and overt infiltration of mixed leukocytes in the lamina propria. However, the turbot fed Ala-Gln diet showed the integrity of the intestinal tissue structure and higher ADC and AKP levels like fish in FM group. Compared to SBM group, the inclusion of 2% Ala-Gln in SBM-basal diet significantly elevated the expression of barrier-forming tight junction proteins claudin-4, occludin and ZO-1 and depressed the expression of pro-inflammatory cytokines TNF-alpha in the intestine. Fish fed Ala-Gln diet showed remarkable increased MUC-2 and PPAR-gamma gene expression as well as reduced expression of NF-kappa B and MLCK equivalent to the level of FM group. Additionally, Gln significantly elevated the relative abundance of Proteobacteria (Vibrio spp.) and declined Bacteroidetes (Bacteroides spp.) relative abundance. The similarity of intestinal microbial communities in Ala-Gln group was notably closer to FM group from PCoA, UPGMA and Heatmap analyses based on weighted UniFrac distance. In conclusion, dietary Gln could probably enhance intestinal barrier function to alleviate enteropathy by improving MUC-2 and PPAR-gamma expression and inhibiting NF-kappa B-MLCK signaling pathway, as well as altering microbiota

Effects of dietary glycinin on the growth performance, digestion, intestinal morphology and bacterial community of juvenile turbot, Scophthalmus maximus L.

This study was run to investigate effects of dietary glycinin on the growth performance, digestion, intestinal morphology and bacterial community of juvenile turbot (Scophthalmus maximus L.). Graded levels (0%, 3%, 6% and 12%) of purified glycinin were added to the basal diet to formulate four experimental diets containing 0%, 2.18%, 4.17% and 8.31% immunologically active glycinin, respectively. Triplicate groups of 30 fish were fed to apparent satiation twice daily for 12 weeks. Dietary inclusion of glycinin did not affect feed intake, feed efficiency ratio or weight gain of turbot, however, fish fed 12% glycinin showed a significant decrease in the apparent digestibility of dry matter and protein, as well as the whole-body lipid content. Meanwhile, slightly increased infiltration of mixed leukocytes in the lamina propria was observed in turbot fed 12% glycinin, so was specific IgM against glycinin in the serum. Sequencing of bacterial 16s rRNA V-4 region showed that Proteobacteria (90.64%), Bacteroidetes (6.01%) and Firmicutes (1.73%) were the dominant bacteria in the intestine of turbot. Dietary inclusion of glycinin had no significant effect on the overall structure of bacterial community but dramatically reduced the relative abundance of the Vibrio genus, one of the core microbes, in a dose-independent manner. Our results suggest that turbot can tolerate a relatively high level of immunologically active glycinin (8.31%) in the diet without showing notable impairments of growth performance and gut function

The relationship between dietary methionine and growth, digestion, absorption, and antioxidant status in intestinal and hepatopancreatic tissues of sub-adult grass carp (Ctenopharyngodon idella)

Abstract Background Methionine is an essential amino acid for fish. The present study was conducted to investigate the effects of dietary methionine on growth performance, digestive and absorptive ability, as well as antioxidant capacity in the intestine and hepatopancreas of sub-adult grass carp (Ctenopharyngodon idella). Results Dietary methionine deficiency significantly decreased percentage weight gain (PWG), feed intake, feed efficiency and protein efficiency ratio, as well as activities of hepatopancreatic glutamate-oxaloacetate transaminase and muscle glutamate-pyruvate transaminase in sub-adult grass carp (P < 0.05). Furthermore, methionine deficiency significantly reduced activities of trypsin, lipase and amylase in the intestine, Na+/K+-ATPase, alkaline phosphatase and γ-glutamyl transpeptidase in three intestinal segments, and creatine kinase (CK) in the proximal intestine (P < 0.05). However, an unexplained and significant increase in CK activity in the mid intestine was associated with dietary methionine deficiency. Malondialdehyde and protein carbonyl contents in the intestine and hepatopancreas were significantly increased by methionine deficiency (P < 0.05), whereas anti-hydroxyl radical capacity in the hepatopancreas and intestine, and anti-superoxide anion capacity in the intestine, were significantly decreased by methionine deficiency (P < 0.05). Moreover, methionine deficiency significantly decreased superoxide dismutase and glutathione reductase activities, glutathione contents in the hepatopancreas and intestine, as well as glutathione peroxidase activity in the intestine (P < 0.05), whereas it significantly increased activities of catalase in the hepatopancreas and glutathione-S-transferase in the hepatopancreas and intestine (P < 0.05). Conclusions The present results demonstrated that dietary methionine deficiency induced poor growth, and decreased digestive and absorptive function and antioxidant capacity in the hepatopancreas and intestine of sub-adult grass carp. Methionine requirements for sub-adult grass carp (450-1, 170 g) based on PWG, intestinal trypsin, and hepatopancreatic anti-hydroxyl radical activities were estimated to be 6.12 g/kg diet (21.80 g/kg protein), 6.99 g/kg diet (24.90 g/kg protein) and 5.42 g/kg diet (19.31 g/kg protein), respectively, in the presence of 1.50 g cysteine/kg (5.35 g/kg protein)

Dietary arginine supplementation mitigates the soybean meal induced enteropathy in juvenile turbot, Scophthalmus maximus L.

A 12-week feeding trial was conducted to investigate the protective effects of arginine on the intestinal health of juvenile turbot (Scophthalmus maximus L.) fed high doses of dietary soybean meal. Sextuple replicates of 30 fish were fed each of four isonitrogenous and isolipidic experimental diets: fish-meal-based diet (FM); FM with 40% fish meal protein replaced by soybean meal protein (SBM); SBM+1% arginine (ARG1) and SBM+2% arginine (ARG2). Turbot-fed SBM showed typical soybean meal-induced enteropathy, characterized by an increase in the thickness of lamina propria, as well as significant decreases in the absorptive surface and activities of intestinal brush border membrane enzymes and Na+, K+-ATPase. On the contrary, fish-fed ARG1 showed enhanced intestinal mucosal barrier function in terms of the enhanced gene expression of anti-inflammatory cytokine and barrier-forming tight junction proteins, as well as depressed gene expression of pro-inflammatory cytokines and pore-forming tight junction proteins. Fish-fed AGR2 showed intermediate intestinal performances between SBM and AGR1. Dietary arginine (1%) also significantly regulated the expression of AMP-activated protein kinase alpha 1 (AMPK alpha 1), myosin light chain kinase (MLCK) and nuclear transcription factor-kappa B p65 (NF-kappa B p65), and these regulations correlated well with its regulations on intestinal mucosal barrier related genes at all sampling time-points. In conclusion, arginine supplementation (1%) in diet for turbot mitigated the soybean meal-induced enteropathy by enhancing the intestinal mucosal barrier function. The activation of AMPK alpha 1 signalling molecule as well as the suppression of NF-kappa B p65 and MLCK signalling molecules may mediate the beneficial effects of arginine