Investigation of nonlinear wave-induced seabed response around mono-pile foundation

YesStability and safety of offshore wind turbines with mono-pile foundations, affected by nonlinear wave effect and dynamic seabed response, are the primary concerns in offshore foundation design. In order to address these problems, the nonlinear wave effect on dynamic seabed response in the vicinity of mono-pile foundation is investigated using an integrated model, developed using OpenFOAM, which incorporates both wave model (waves2Foam) and Biot’s poro-elastic model. The present model was validated against several laboratory experiments and promising agreements were obtained. Special attention was paid to the systematic analysis of pore water pressure as well as the momentary liquefaction in the proximity of mono-pile induced by nonlinear wave effects. Various embedment depths of mono-pile relevant for practical engineering design were studied in order to attain the insights into nonlinear wave effect around and underneath the mono-pile foundation. By comparing time-series of water surface elevation, inline force, and wave-induced pore water pressure at the front, lateral, and lee side of mono-pile, the distinct nonlinear wave effect on pore water pressure was shown. Simulated results confirmed that the presence of mono-pile foundation in a porous seabed had evident blocking effect on the vertical and horizontal development of pore water pressure. Increasing embedment depth enhances the blockage of vertical pore pressure development and hence results in somewhat reduced momentary liquefaction depth of the soil around the mono-pile foundation.Energy Technology Partnership (ETP), Wood Group Kenny, and University of Aberdeen; the National Science Fund for Distinguished Young Scholars (51425901) and the 111 project (B12032)

Engineering hibiscus-like riboflavin/ZIF-8 microsphere composites to enhance transepithelial corneal cross-linking

Riboflavin-5-phosphate (RF) is the most commonly used photosensitizer in corneal cross-linking (CXL), but its hydrophilicity and negative charge limit its penetration through the corneal epithelium into the stroma. To enhance the corneal permeability of RF and promote its efficacy in the treatment of keratoconus, novel hibiscus-like RF@ZIF-8 microsphere composites [6RF@ZIF-8 NF (nanoflake)] are prepared using ZIF-8 nanomaterials as carriers, which are characterized by their hydrophobicity, positive potential, biocompatibility, high loading capacities, and large surface areas. Both hematoxylin and eosin endothelial staining and TUNEL assays demonstrate excellent biocompatibility of 6RF@ZIF-8 NF. In in vivo studies, the 6RF@ZIF-8 NF displayed excellent corneal permeation, and outstanding transepithelial CXL (TE-CXL) efficacy, slightly better than the conventional CXL protocol. Furthermore, the special hibiscus-like structures of 6RF@ZIF-8 NF meant that it has better TE-CXL efficacy than that of 6RF@ZIF-8 NP (nanoparticles) due to the larger contact area with the epithelium and the shorter RF release passage. These results suggest that the 6RF@ZIF-8 NF are promising for transepithelial corneal cross-linking, avoiding the need for epithelial debridement

Comparative study of carbohydrate levels on growth, oxidative stress and glucolipid metabolism of hybrid fish between Megalobrama amblycephala (♀) × Culter alburnus (♂) and Culter alburnus

The present study used hybrid fish (Megalobrama amblycephala ♀ × Culter alburnus ♂, abbreviated as BT) and topmouth culter (Culter alburnus, abbreviated as TC) as research subjects to assess and compare the effects of carbohydrate on the growth, oxidative stress and glucolipid metabolism of the two fish. The TC (initial weight, 13.10 ± 0.10 g) and BT (initial weight, 12.85 ± 0.13 g) were fed isonitrogenous (43% crude protein) and isolipidic (6.5% crude lipid) diets with carbohydrate levels of 10% (LC diet) and 30% (HC diet) for 11 weeks, respectively. The results showed that the HC diet resulted in a significant decrease in specific growth rate (SGR) of both fish. However, the SGR in BT was significantly higher than in TC, regardless of diet. Furthermore, HC diet significantly increased serum alanine transaminase (GPT) and hepatic malondialdehyde (MDA) content, decreased hepatic catalase (CAT) activity and resulted in increased hepatocyte volume, nucleus deficiency and nucleus deviation from the center of cytoplasm in both fish. However, BT had significantly higher glutathione peroxidase (GPx) activity and lower serum GPT and aspartate transaminase (GOT) content compared to TC. The HC diet induced significant increases in hepatosomatic index (HSI), liver lipid droplet area, liver glycogen, serum glucose (GLU) and triglyceride (TG) content in both fish. However, HSI and lipid droplet area were significantly higher in BT than in TC, while serum GLU and TG content were significantly lower in BT than in TC. Both fish can adapt to the HC diet by up-regulating the expression of glycolysis-related gene (glucokinase (gk)) and lipogenesis-related genes (acetyl-CoA carboxylase a (acca), fatty acid synthase (fas)). However, the expression levels of glucose transporter 2 (glut2), glycolysis-related gene (phosphofructokinase liver b (pfklb)) and lipogenesis-related genes (sterol regulatory element-binding protein 1 (srebp1), ATP citrate lyase a (aclya)) were increased only in BT fed HC diet. In summary, the BT liver has stronger glucose transport, glycolysis, and lipid tolerance compared to TC, thus exhibiting better glucose homeostasis and growth performance. It indicates that hybridization may help to produce new strain of fish with high carbohydrate utilization capacity

The reliability assessment of the electromagnetic valve of high-speed electric multiple units braking system based on two-parameter exponential distribution

In order to solve the reliability assessment of braking system component of high-speed electric multiple units, this article, based on two-parameter exponential distribution, provides the maximum likelihood estimation and Bayes estimation under a type-I life test. First of all, we evaluate the failure probability value according to the classical estimation method and then obtain the maximum likelihood estimation of parameters of two-parameter exponential distribution by performing and using the modified likelihood function. On the other hand, based on Bayesian theory, this article also selects the beta and gamma distributions as the prior distribution, combines with the modified maximum likelihood function, and innovatively applies a Markov chain Monte Carlo algorithm to parameters assessment based on Bayes estimation method for two-parameter exponential distribution, so that two reliability mathematical models of the electromagnetic valve are obtained. Finally, through type-I life test, the failure rates according to maximum likelihood estimation and Bayes estimation method based on Markov chain Monte Carlo algorithm are, respectively, 2.650 × 10 −5 and 3.037 × 10 −5 . Compared with the failure rate of a electromagnetic valve 3.005 × 10 −5 , it proves that the Bayes method can use a Markov chain Monte Carlo algorithm to estimate reliability for two-parameter exponential distribution and Bayes estimation is more closer to the value of electromagnetic valve. So, by fully integrating multi-source, Bayes estimation method can preferably modify and precisely estimate the parameters, which can provide a certain theoretical basis for the safety operation of high-speed electric multiple units

Use of fly-ash slurry in backfill grouting in coal mines

Cave backfill grouting implies grouting of the caving rock mass prior to it being compacted. The filling materials strengthen the caving rock and support the overlying strata to achieve the purpose of slowing down the surface subsidence. The broken roof will fail and collapse during mining operations performed without appropriate supporting measures being taken. It is difficult to perform continuous backfill mining on the working face of such roofs using the existing mining technology. In order to solve the above problems, fly ash and mine water are considered as filling materials, and flow characteristics of fly-ash slurry are investigated through laboratory experiments and theoretical analyses. Laws governing the diffusion of fly-ash slurry in the void of caving rock masses and in the void between a caving rock mass and a basic roof are obtained and verified. Based on the results obtained from the above analyses and actual conditions at the Zhaoguan coal mine, Shandong Province, China, a cave backfill grouting system of the hauling pipeline is developed and successfully tested at the 1703 working face in the Zhaoguan coal mine. The results demonstrate that a filling rate of 43.46% is achieved, and the surface subsidence coefficient of the grouting process is found to be 0.475. Compared to the total caving method, the proposed system is found to achieve a reduction rate of 40.63%. This effectively helps in lowering the value of the surface subsidence coefficient. Fly ash and mine water, considered as primary materials in this study, also play a significant role in improving the air quality and water environment

Effects of composite mixture of protein sources in replacing fish meal on nutritional value and flavor quality of Pacific white shrimp (Litopenaeus vannamei)

An 8-week feeding trial was conducted to investigate the effects of fish meal partially or totally replaced with poultry by-product meal (PBM), antarctic krill meal (AKM), corn gluten meal (CGM), cottonseed meal (CM) and rice protein concentrate meal (RPM) on amino acids, fatty acids, nucleotides and volatile compounds of Pacific white shrimp (Litopenaeus vannamei). Results showed that shrimps fed with partial replacement of fish meal (50 %) with AKM and PBM (1:1) significantly increased the content of inosine monophosphate (IMP), the proportion of eicosapentaenoic acid (EPA), n-9 monounsaturated fatty acids (MUFAs), and significantly decreased the content of hypoxanthine (Hx), benzaldehyde, and the proportion of saturated fatty acids (SFAs). Dietary fish meal totally replaced by the whole-plant protein diet resulted in a lower value of essential amino acids to total amino acids (EAA / TAA), n-3 / n-6 PUFAs, and a lower proportion of docosahexaenoic acid (DHA), n-3 polyunsaturated fatty acid (PUFAs). Principal component analysis and hierarchical cluster analysis revealed that shrimps fed diet with fish meal partially replaced by AKM and PBM (1:1) had the most similar volatile compounds profile to the fish meal-based diet. These results indicated that the composite mixture of PBM and AKM (1:1) is an excellent substitution for fish meal in shrimp diets

Effects of Dietary Paper Mulberry (Broussonetia papyrifera) on Growth Performance and Muscle Quality of Grass Carp (Ctenopharyngodon idella)

The present study investigated the effects of dietary paper mulberry (Broussonetia Papyrifera, BP) on growth performance, muscle quality and muscle growth-related mRNA expressions of grass carp. Fish (initial weight: 50.0 ± 0.5 g) were fed diets supplemented with 0% (control diet), 5%, 10%, 15% and 20% BP for 8 weeks. The results showed that increasing levels of paper mulberry linearly and quadratically decreased the special gain rate (SGR) and increased the feed conversion rate (FCR) of grass carp (p < 0.05). Significantly positive quadratic trends were found between paper mulberry levels and muscle crude fat or crude protein of grass carp (p < 0.05). In comparison to the control diet, the 10%BP and 15%BP groups had significantly decreased muscle crude fat and increased crude protein (p < 0.05). The levels of paper mulberry resulted in a linear and quadratic increase in water loss of grass carp muscle (p < 0.05), and all groups with paper mulberry supplementation were significantly higher than the control group (p < 0.05). Significant positive linear and quadratic trends were found between the paper mulberry levels and muscle fiber diameter or density of grass carp (p < 0.05). In comparison to the control diet, the significant differences were found in the 15%BP and 20%BP groups (p < 0.05). The muscle adhesiveness and hardness linearly and quadratically increased with the increasing levels of paper mulberry (p < 0.05), and both of which increased significantly when the level of paper mulberry reached 10% (p < 0.05). In addition, the increase in paper mulberry linearly and quadratically improved the expressions of myoblast determination protein (MyoD), myogenin (MyoG), paired box protein 7 (Pax7) and myostatin 1 (MSTN1) (p < 0.05). When the supplementation of paper mulberry reached 15%, the expressions of all these mRNAs were significantly higher than those of the control group (p < 0.05). In summary, adding 5% paper mulberry did not affect the growth of grass carp. However, the supplementation of 10% paper mulberry could improve muscle quality through improving muscle hardness, reducing fat accumulation and muscle fiber diameter, at the cost of reducing growth performance

Effects of fermented Broussonetia papyrifera on growth, intestinal antioxidant, inflammation and microbiota of grass carp (Ctenopharyngodon idella)

The present study was conducted to investigate the influence of fermented Broussonetia Papyrifera (FBP) on growth performance, intestinal antioxidant capacity, inflammation and microbiota of grass carp. Fish (initial weight: 50.0 ± 0.5 g) were fed diets with 0 (control diet), 5 % (FBP5), 10 % (FBP10), 15 % (FBP15) and 20 % (FBP20) of FBP supplementation respectively for 8 weeks. The results showed that FBP5 group significantly decreased FCR of grass carp (P < 0.05). Besides, FBP supplementation significantly decreased intestine Cu/Zn SOD activity (P < 0.05), as well as significantly elevated mRNA expression level of kelch-like-ECH-associated protein 1 (keap1) and depressed mRNA expression level of NF-E2-related factor 2 (nrf2), superoxide dismutase 1 (sod1) and catalase (cat) (P < 0.05). The content of malondialdehyde (MDA) increased significantly in the FBP20 group compared to the control diet (P < 0.05). The expression level of interleukin-8 (il-8) and interferon γ (ifnγ) downregulated with increased dietary FBP, and significant difference was found in FBP20 group (P < 0.05). In addition, when the supplementation of FBP was no more than 15 %, the abundance of Firmicutes and Fusobacteria increased significantly, while the abundance of Actinobacteria and Cyanobacteria decreased significantly in intestine of grass carp (P < 0.05). Compared to the control diet, the richness and diversity of intestinal microbiota of grass carp decreased significantly in FBP20 group (P < 0.05). According to the second order polynomial regression equation analysis of SGR and FCR, the optimal additional level of FBP was estimated to be 4.58 % and 5.28 %, respectively. The recommended maximum addition of FBP in diet of grass carp was up to 15 % according to the results of intestinal microbiota

Expression and prognosis analyses of the <i>Tob/BTG</i> antiproliferative (<i>APRO</i>) protein family in <i>human</i> cancers

<div><p>Background</p><p>Despite advances in early diagnosis and treatment, cancer remains the major cause of mortality in the world. The <i>Tob/BTG</i> antiproliferative (<i>APRO</i>) protein family is reported to participate in diverse human diseases. However, there’s little known about their expression and prognostic values in most human cancers.</p><p>Methods</p><p>We performed a detailed cancer vs. normal analysis. The mRNA expression levels of <i>APRO</i> family in various cancers were analyzed via the Oncomine database. Moreover, the Kaplan-Meier Plotter and PrognScan databases were used to evaluate the prognostic values.</p><p>Results</p><p>We observed that the mRNA expression levels of <i>TOB1-2</i> and <i>BTG2</i> were decreased in most cancers compared with normal tissues, while <i>BTG3</i> was upregulated in most cancers. In survival analyses based on Kaplan-Meier Plotter, <i>TOB1</i>, <i>BTG1</i> and <i>BTG4</i> showed significant associations with survival outcome of different subtypes of breast cancer. Decreased <i>BTG2</i> was related with poor relapse free survival (RFS) in all subtypes of breast cancer. Especially, besides RFS, reduced <i>BTG2</i> also indicated worse overall survival and distant metastasis free survival in breast cancer patients who were classified as luminal A. Significant prognostic effects of the whole <i>APRO</i> family were also found in lung adenocarcinoma, but not in squamous cell lung carcinoma. In addition, potential correlations between some <i>APRO</i> family members and survival outcomes were also observed in ovarian, colorectal and brain cancer.</p><p>Conclusions</p><p>Some members of <i>APRO</i> family showed significant expression differences between cancer and normal tissues, and could be prognostic biomarkers for defined cancer types.</p></div