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Ovomucin (OVM) is a natural glycoprotein with various biological activities but poor solubility. This study aimed to enhance the solubility of OVM by using an ultrasonic-assisted method. The effect of ultrasound (US) on the structure, thermal stability and biological functions of OVM aggregates was evaluated. It was found that insoluble OVM aggregates were dissociated and the solubility increased significantly to 90.0 % after US under 400 W for 45 min. US also improved the onset temperature (To) and denaturation temperature (Td) of OVM. More importantly, the cholesterol binding capacity of both OVM and its digestion products were significantly improved after US (p 0.05). The gastrointestinal digestion products of US-OVM also showed higher α-amylase and α-glucosidase inhibition than native OVM aggregates. US-induced dissociation of OVM aggregates and the conversion of β-sheet and β-turn to random coil, resulting in the exposure of hydrophobic binding sites may be an important reason for the enhanced stability and adsorption capacity. These findings suggested that US was an effective method for preparing soluble OVM and improved its adsorption capacity, which can further facilitate the application of OVM in the food industry.

With the rapid development of power energy, electronic information, rail transit, and aerospace industries, nanocomposite dielectric materials have been widely used as new materials. Polymer/inorganic nanocomposite dielectric materials possess excellent physical and mechanical properties. In addition, numerous unique properties such as electricity, thermal, sound, light, and magnetic properties are exhibited by these materials. First, the macroscopic quantum tunneling effect, small-size effect, surface effect, and quantum-size effect of nanoparticles are introduced. There are a few anomalous changes in the physical and chemical properties of the matrix, which are caused by these effects. Second, the interaction mechanism between the nanoparticles and polymer matrix is introduced. These include infiltration adsorption theory, chemical bonding, diffusion theory, electrostatic theory, mechanical connection theory, deformation layer theory, and physical adsorption theory. The mechanism of action of the interface on the dielectric properties of the composites is summarized. These are the interface trap effect, interface barrier effect, and homogenization field strength effect. In addition, different interfacial structure models were used to analyze the specific properties of nanocomposite dielectric materials. Finally, the research status of the dielectric properties of nanocomposite dielectric materials is introduced.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that can result in considerable disability and pain. The metacarpophalangeal (MCP) joint is the most common diseased joint in RA. In clinical practice, MCP synovitis is commonly diagnosed on the basis of musculoskeletal ultrasound (MSUS) images. However, because of the vague criteria, the consistency in grading MCP synovitis based on MSUS images fluctuates between ultrasound imaging practitioners. Therefore, a new method for diagnosis of MCP synovitis is needed. Deep learning has developed rapidly in the medical area, which often requires a large-scale data set. However, the total number of MCP-MSUS images fell far short of the demand, and the distribution of different medical grades of images was unbalanced. With use of the traditional image augmentation methods, the diversity of the data remains insufficient. In this study, a high-resolution generative adversarial network (HRGAN) method that generates enough images for network training and enriches the diversity of the training data set is described. In comparison experiments, our proposed diagnostic system based on MSUS images provided more consistent results than those provided by clinical physicians. As the proposed method is image relevant, this study might provide a reference for other medical image classification research with insufficient data sets.

Objective A polarized macrophage response plays a critical role in the pathophysiological process of myocardial infarction (MI). Several studies have shown a pro-inflammatory role for monomeric C-reactive protein (mCRP) in cardiovascular disease. However, the mechanism of how mCRP regulates macrophage phenotype switching remains unknown. In the present study, the effect of mCRP on macrophage polarization and its pathological function in myocardial repair after myocardial infarction was investigated. Methods MI was induced by permanent ligation of the left anterior descending coronary artery in ICR mice. Adult mice were injected with mCRP (2.5 mg/kg) with or without SP600125 (15 mg/kg, JNK inhibitor) 45 min before MI. The cardiac function, scar size as well as cardiac fibrosis, infiltration of inflammatory cells, and the level of proteins in the JNK signaling pathway in infarcted myocardium were assessed. In addition, the phenotypic characterization of macrophages was further measured by ELISA, flow cytometry and quantitative RT-PCR in cultured THP-1 cells or peritoneal macrophages. Results Cardiac function deterioration, ventricular dilatation and fibrosis were exacerbated in mice pretreatment with mCRP following MI. Meanwhile, an increased accumulation of infiltrated inflammatory cells in infarcted myocardium was observed in the mCRP group. Moreover, activation of the JNK signaling pathway was markedly elevated in mCRP treated animals post-MI. In contrast, pharmacological inhibition of JNK phosphorylation activity by SP600125 muted the detrimental effects of mCRP in MI mice. Furthermore, in vitro and in vivo co-culture experiments showed that mCRP shifted macrophage polarization towards pro-inflammatory phenotypes, and this polarization could be abolished by sp600125. Conclusion Taken together, our results imply that mCRP impairs myocardial repair after myocardial infarction by polarizing the macrophages into the pro-inflammatory M1 phenotype via the JNK-dependent pathway., Graphical Abstract

As novel fluorescent nanomaterials, carbon dots have attracted increasing research attention because of their simple synthesis, robust fluorescence, low toxicity, and easy functionalisation. Previous research was focused on preparing carbon dots from biomass and chemical materials; however, most of these carbon dots exhibited blue fluorescence. Moreover, the fluorescence quantum yield was generally low, significantly limiting their application in biological imaging. To broaden the application scope of carbon dots, this study prepared long-wavelength emitting nano-carbon dots that exhibited increased quantum yield. Novel N-doped yellow fluorescent nano-carbon dots (Y-CDs) were synthesised via a hydrothermal method using L-tartaric acid and urea as the precursors. The Y-CDs had a high quantum yield (15.9%) and demonstrated photostability at various pHs, temperatures, and ionic strengths. The Y-CDs could detect cobalamin effectively and selectively, showing a linear relationship between fluorescence intensity and cobalamin concentration. The related coefficient was 0.997, and the detection limit was 2.101 μmol/L. In addition, the Y-CDs were successfully used as an imaging probe for MDA-MB-231 cells. Therefore, the Y-CDs developed in this study can be used for cobalamin detection and cell imaging.

Hybrid bonded/bolted (HBB) joint has been widely used in engineering practice because it can overcome the potential weakness of pure bonded and pure bolted joints. However, studies on HBB joint are still at the initial stage. In this paper, tensile properties of a composite–metal single-lap HBB joint was investigated experimentally. And a detailed finite element model (FEM) was established to simulate the tensile behavior of the joint. The model was verified by the experimental results. Then the damage propagation and load transfer mechanism were explored based on the FEM. The results show that the HBB joint can provide multi-load transmission paths and resist damage propagation in the adhesive. The HBB joint has higher strength and energy absorption capacity than the pure bonded joint. And the HBB joint has greater initial damage load and tensile stiffness than pure bolted joint. Adhesive fillets can obviously improve the tensile performances of the HBB joint. Lateral stiffness of the joint boundary and testing machine show obvious effects on tensile performances of single-lap hybrid joints.

Tensile experiments were conducted with single-bolted and multi-bolted countersunk composite-metal joints. The finite element models with Hashin criteria and modified Camanho degradation law were developed to predict the bearing load and to simulate the failure behavior. The models were validated with the experimental results, including load-displacement curves and composite damage profiles. Based on the verified models, bolt load distributions of multi-bolted joints were calculated and analyzed before and after damage occurs. Results show that composite damages can change the bolt load distributions to a certain extent, which needs to be considered during the structure design. To adjust the bolt load distribution, the effects of joint variables, including bolt-hole clearance, bolt spacing, countersunk height ratio, and bolt stiffness combination, have been studied. It is found that the increase of the pin clearance around the largest bearing bolt would decrease its corresponding bearing load. The countersunk height ratio affects the bolt load distribution difference that a greater ratio leads to a less difference. The bolt spacing and bolt stiffness can also be used to reduce the bolt load distribution difference with elaborately designed combinations.

Polyethylene, with its excellent mechanical and dielectric properties is used as an insulator for high-voltage direct current (HVDC) transmission. In ultra-high-voltage direct current (UHVDC) transmission, the ageing of insulation materials caused by space charge under high DC voltage becomes serious. Therefore, restraining the space charge and improving the dielectric properties of HVDC cables is important. In this study, low-density polyethylene (LDPE) was used as the raw material and combined with cooling media in a vulcanizing press. A polarizing microscope was used to observe the samples’ crystal morphologies. The space charge accumulation and dispersion were detected using pulsed electro-acoustic. Additionally, dielectric properties such as electrical conductivity and dielectric frequency spectrum were tested. The grain size in the air-cooled LDPE samples was found to be large and unevenly dispersed. However, the grain sizes in the water and oil cooling LDPE samples were small. The mean charge density of the oil cooling samples was the lowest. Under a short circuit measurement, more space charges were found in the natural and rapid air cooling samples. The mean charge densities of these two samples were high, with a fast decay rate. With an 8 and 50 kV/mm electric field strength, the oil cooling samples’ conductivity was the highest and lowest, respectively.

Falls are the leading cause of fatal and non-fatal injuries among older adults. Evidence-based fall prevention programs are delivered nationwide, largely supported by funding from the Administration for Community Living (ACL), to mitigate fall-related risk. This study utilizes data from 39 ACL grantees in 22 states from 2014 to 2017. The large amount of missing values for falls efficacy in this national database may lead to potentially biased statistical results and make it challenging to implement reliable variable selection. Multiple imputation is used to deal with missing values. To obtain a consistent result of variable selection in multiply-imputed datasets, multiple imputation-stepwise regression (MI-stepwise) and multiple imputation-least absolute shrinkage and selection operator (MI-LASSO) methods are used. To compare the performances of MI-stepwise and MI-LASSO, simulation studies were conducted. In particular, we extended prior work by considering several circumstances not covered in previous studies, including an extensive investigation of data with different signal-to-noise ratios and various missing data patterns across predictors, as well as a data structure that allowed the missingness mechanism to be missing not at random (MNAR). In addition, we evaluated the performance of MI-LASSO method with varying tuning parameters to address the overselection issue in cross-validation (CV)-based LASSO.

Few data are available on hospital-wide incidence of central line-associated bloodstream infection (CLABSI) rates in patients with central venous catheter (CVC) in China, where many systemic obstacles holding back evidence-based guidelines implementation exist.This study was conducted prospectively in 2 phases. The baseline and intervention phases were performed in a teaching hospital in China, between January 2017 and October 2018. A systematic quality improvement (SQI) and multidisciplinary teamwork (MDT) CLABSI infection control program was introduced in the intervention phase. In the intensive care units (ICUs) and non-ICUs, CLABSIs were continuously monitored, data collected, then analyzed.After intervention, the CLABSI rate decreased from 2.84-0.56 per 1,000 CVC days in ICUs (P.001), and from 0.82-0.47 per 1,000 CVC days in non-ICUs (P = .003). The length of time until CLABSI occurrence increased from 8.72-13.60 days in ICUs (P = .046), and from 10.00-12.00 days in non-ICUs (P = .048). The number of multidrug-resistant bacteria isolated from CLABSI episodes decreased both in ICUs and in non-ICUs.The SQI and MDT CLABSI infection control program is effective in reducing hospital-wide CLABSI in patients with CVC, both in ICUs and in non-ICUs.

The present work aimed to fabricate food-grade Pickering emulsions stabilized by heteroprotein complexes formed by ovotransferrin (OVT) and lysozyme (LYS) as lipid-based nutraceutical delivery vehicles. The heteroprotein complexation, as confirmed by turbidity titrations, was proved to be an effective means to prepare food-grade particles. Multiple parameters such as particle size, zeta potential and dispersion stability were characterized in screening for proper OVT–LYS particles as Pickering stabilizers. OVT–LYS particles with OVT/LYS ratio of 8:1 at pH 9.3 met all requirements of eligible Pickering stabilizers such as intermediate wettability. Titrations in the presence of sodium chloride demonstrated that primary driving force of OVT–LYS particle formation was electrostatic attraction. Afterwards, food-grade Pickering emulsions were fabricated using OVT–LYS particles. Visual observation indicated that Pickering emulsions stabilized by OVT–LYS particles at various particle concentrations and oil fractions were stable during one-month storage at room temperature, and OVT–LYS particles could stabilize high internal phase Pickering emulsions at oil fraction of 0.75. Rheological measurements revealed that viscosity and gel-like structures of Pickering emulsions were dependent on particle concentration and oil fraction. When compared with the extent of lipolysis (32.1%) in bulk oil, the extent of lipolysis (71.5%) in OVT–LYS particle-stabilized Pickering emulsion was increased by 39.4%. Curcumin bioaccessibility was increased from 16.1% to 38.3% after encapsulation of curcumin into OVT–LYS particle-stabilized Pickering emulsion. Such improved bioaccessibility demonstrated that OVT–LYS particle-stabilized Pickering emulsion was an effective delivery vehicle for curcumin.

Bolted composite joints are one of the most common joining methods used in aerospace industry for joining of parts and sub-assemblies, where there is a need to transfer high load with consistency a...

Composite-to-metal 2D (two dimensional) scarf bonded joint (SBJ) specimens with 4scarf angles were tested to study their tensile behaviors. Based on the experimental results, progressive damage finite element models (FEM) were established in ABAQUS/Standard, and the effects of three variables: the metal material, composite stacking sequence and adhesive properties, with respect to the joint tensile properties were investigated. The results show that the metal plasticity and scarf angle can affect the tensile plastic behavior of the joint. Compared with Q235 (steel), 7075-T6 (aluminium) and 30CrMnSiNi2A (steel) plates, TC4 (titanium) plate makes the joint possess higher tensile strength. Changing the composite plate (laminate) stacking sequences can result in the variation of plastic behavior and failure location of the joints. The adhesive properties have significant effects on the joint plastic behavior and ultimate loads.

The over-ply covering the bondline in scarf-repaired laminates can avoid direct exposure of the adhesive to moisture environment which would decrease the properties of the adhesive. The effect of the over-ply on moisture absorption behavior of scarf-repaired composite laminate was studied in this paper. 3D finite element models (FEMs) of scarf-repaired laminates with and without over-ply were established to simulate the moisture absorption behavior and verified by experimental results. Then these models were used to investigate the effects of some factors, including over-ply type, configuration, direction and number, on moisture absorption behavior of the repaired structures, especially of the adhesive. The results show that the over-ply can efficiently decelerate moisture absorption of the adhesive and delay the time of its moisture absorption equilibrium. Over-ply type has effect on moisture absorption of the adhesive. Woven over-ply is more effective to protect the adhesive in repaired laminates from moisture absorption than unidirectional over-ply. For the laminates with only large-circle bonding surface covered, over-ply lap length, configuration and direction are not very important parameters to affect the moisture absorption.

A 3D progressive model with better convergence property is established to capture the mechanical properties and damage mechanism of a composite bolted π-joint under bending load and shown to closely match experimental results. This model is then used to investigate the effect of internal laminate stacking sequence and surface layers thickness on the bending performance of the joint. It was found that the stacking sequence and the surface layers thickness have a significant effect on the matrix crack and delamination distributions in the joint, respectively. Local surface layer thickness can be designed to control the delamination damage around the bolt hole. Finally, volume fraction of 0° layer in the internal laminate and surface layer thickness are used to improve the joint bending performances by proper design.

In this article, the nano-MgO particles were used as inorganic fillers, and polypropylene (PP) polymer was used as a matrix. The nano-MgO/PP composites were prepared by double melt blending. Using the polarization microscope (PLM) test and hot-stage microscope test, the crystalline morphology of PP and nano-MgO/PP with different mass fraction were observed. Using the differential scanning calorimetry (DSC) test, the parameters and crystallinity in the process of isothermal crystallization could be obtained. Additionally, the samples of pure PP and nano-MgO/PP composites were dealt with using a breakdown test and a dielectric frequency spectra test. From the experimental results, nano-MgO particle doping decreased the samples&rsquo, crystal size, and the crystalline structure was converted from large spherulites to fascicled crystallization. Additionally, the crystallization rate became fast and crystallinity increased. According to the breakdown test, the nano-MgO particle doping made the composites form small, dense spherulites. The breakdown developed through a longer path, so the composites&rsquo, breakdown strength rose greatly. When the mass fraction of nano-MgO particles was 3%, the shape parameter of the composites&rsquo, Weibull distribution &beta, was larger, which illustrated that the nano-MgO particles were dispersed uniformly in the PP matrix. According to the dielectric frequency spectra test, the dielectric constant of different nanocomposites were all lower than which of pure PP, but the loss angle tangent values were all higher than which of pure PP.

In this article, the melting blend was used to prepare the Micro-ZnO/LDPE, Nano-ZnO/LDPE and Micro-Nano-ZnO/LDPE with different inorganic particles contents. The effect of Micro-ZnO and Nano-ZnO particles doping on interface microdomain and corona-resistance breakdown characteristics of LDPE composite could be explored. Based on the energy transfer and heat exchange theory of energetic electrons, the inner electrons energy transfer model of different ZnO/LDPE composites was built. Besides, the microstructure and crystalline morphology of inorganic ZnO-particles and polymer composites were detected by SEM, XRD, FTIR, PLM and DSC test, and the AC breakdown and corona-resistance breakdown characteristics of composites could be explored. From the experimental results, the Nano-ZnO particles after surface modification dispersed uniformly in LDPE matrix, and the nanoparticles agglomeration almost disappeared. The inorganic particles doping acted as the heterogeneous nucleation agent, which improved the crystallization rate and crystallinity of polymer composites effectively. The ZnO particles with different size doping constituted the different interface structure and crystalline morphology, which made different influence on composites macroscopic properties. When the Nano-ZnO particle size was 40nm and the mass fraction was 3%, the breakdown field strength of Nano-ZnO/LPDE was the highest and 15.8% higher than which of pure LDPE. At the same time, the shape parameter &beta, of Micro-Nano-composite was the largest. It illustrated the microparticles doping reduced the probability of nanoparticles agglomeration in matrix. Besides, both Micro-ZnO and Micro-Nano-ZnO particles doping could improve the ability of corona corrosion resistance of LDPE in varying degrees. The corona-resistant breakdown time order of four samples was as follows: LDPE&lt, Micro-ZnO/LDPE &lt, Nano-ZnO/LDPE&lt, Micro-Nano- ZnO/LDPE. When the mass fraction of Micro-ZnO and Nano-ZnO particles was 2% and 3% respectively, the corrosion depth and area of Micro-Nano- ZnO/LDPE was the least, and the ability of corona corrosion resistance was the strongest.

We describe a highly efficient one-enzyme procedure using ω-transaminase in the absence of expensive cofactor (NAD(P)H)-dependent enzymes used for a by-product removal process. The aromatic amino donor benzylamine, enabling its acceptance by transaminases with either (R)- or (S)-enantioselectivity, was used, allowing reactions to proceed in excellent conversions using only 3 equivalents of the amino donor. During the transamination reaction, the generated co-product aldehyde was irreversibly converted to its corresponding carboxylic acid assisted by aerobic oxidation with 1 atmosphere of oxygen, therefore the equilibrium was successfully pushed to the product side. The aerobic oxidation promoted transamination, and the corresponding method was compatible with a wide spectrum of ω-transaminases. The amino donor used here is easily and commercially obtainable, and is suitable for low-cost and scalable preparations, representing a promising pathway for clean synthesis of high value-added chiral amines.

Low-velocity impact performance of scarf-repaired composite laminates was investigated by experimental and numerical methods. The numerical model was built using continuum damage mechanics and cohesive elements were used in all the interfaces of the adherends (i.e. the patch and the parent). The model was verified to be efficient. Based on it, damage profiles and damage mechanism were studied, and the effects of the scarf angle, the adhesive thickness and the patch off-axis angles were analyzed. Results show that the patch damage occurs in its center region through the thickness, while the damages in the parent and adhesive mainly occur around the back face. Damage area of the patch is obviously more serious than that of the parent, and the adhesive can protect the parent to some degree. The scarf angle, the adhesive thickness and the patch off-axis angles have effects on the impact properties. The scarf angles ranging from 7° to 8°, the adhesive thicknesses of 0.15 mm, the patch off-axis angles ranging from 135° to 160° are recommended for better impact performances.

Composite-metal joints with a metal insert are one kind of connecting structure. In this paper, tensile experimental tests were carried out to investigate tensile properties of a composite-metal joint with a novel metal insert design. Finite element models of the joint were established, and strain distribution and tensile strength were analyzed. The numerical results are in good agreement with the experimental results. Results show that the joint failure is dominated by shear properties of the resin layer. Increasing the resin layer thickness in a certain range will improve the tensile strength of the joint, while increasing the radius of the fillet on the ending side of the metal insert will decrease the joint strength. Increasing the resin layer plasticity will improve the joint strength. The effect of the embedded depth of the metal insert can be ignored.

The present study aimed to assemble protein fibril-polysaccharide hydrogels as nutraceutical delivery vehicles. Turbidity titrations confirmed that complexations between ovotransferrin (OVT) fibrils and xanthan gum (XG) indeed occurred, and electrostatic interaction was the major driving force of OVT fibril-XG complexation. After optimization of the pH and acidifier, stable OVT fibril-XG hydrogels could be fabricated by adjusting the pH to 4.0 with glucono delta-lactone. To better understand the physicochemical properties of OVT fibril-XG gel, characterization of XG gel was also conducted. Scanning electron microscopy indicated that OVT fibril-XG gel had a denser network than XG gel. Rheological measurements revealed that OVT fibril-XG gel had higher gel strength and viscosity than XG gel. OVT fibril-XG gel and XG gel could be used as dihydromyricetin (DMY) delivery vehicles with a higher DMY loading (2 mg mL-1). DMY release was investigated using an in vitro gastrointestinal digestion model. All DMY was released from OVT fibril-XG gel after gastrointestinal digestion, and only 41.7% of DMY was released from XG gel after gastrointestinal digestion, indicating that OVT fibril-XG gel was more efficient in DMY delivery. DMY was released via a non-Fickian transport mechanism in both OVT fibril-XG gel and XG gel. The results of this study could provide new insight into the assembly of protein fibril-polysaccharide hydrogels and rational design of hydrogels as nutraceutical delivery vehicles.

Low density polyethylene (LDPE) doped with inorganic nano-MMT and nano-ZnO particles improved the dielectric properties of the cable insulation layer. In this article, nano-MMT/LDPE and nano-ZnO/LDPE composites were prepared by polymer intercalation and melt blending, respectively. The octadecyl quaternary ammonium salt and silane coupling agent were applied for surface modification in nano-MMT and nano-ZnO particles, and this then improved the compatibility of nanoparticles and polymeric matrix. These samples were characterized by FTIR, PLM, DSC and TSC, from which the effect of nanoparticles doping on polymer crystal habit and interface traps would be explored. In these experiments, the AC breakdown characteristics and space charge characteristic of different composites were studied. The experimental results showed that the interface bonding of nanoparticles and polymer was improved by coupling agents modifying. The dispersion of nanoparticles in matrix was better. When the mass fraction of nanoparticles doping was 3 wt.%, the crystallization rate and crystallinity of composites increased, and the crystalline structure was more complete. Besides, the amorphous regions in material decreased and the conducting channel was circuitous. At this time, the breakdown field strength of nano-MMT/LDPE and nano-ZnO/LDPE increased by 10.3% and 11.1%, compared to that of pure LDPE, respectively. Furthermore, the density and depth of interface traps in polymer increased with nanoparticles doping. Nano-MMT and nano-ZnO could both restrain the space charge accumulation, and the inhibiting effect of nano-ZnO was more visible.

Presented is the first example of synthesizing an array of primary-, secondary-, and tertiary-α-ketoamides in moderate to excellent yields with a catalyst nBu4NI from methyl ketones and amine/ammonium salts under mild conditions using oxidant TBHP.

The first example of catalyst-free aerobic oxidation of aldehydes in water under respective acidic, neutral and alkaline conditions was developed. The sole oxidant is molecular oxygen of 1 atmosphere and reactions can proceed under extremely mild conditions. This procedure covers a wide range of aldehydes, and operates easily. No additives and catalysts were required for this purpose, and most of the aldehydes can be converted to their corresponding carboxylic acids with good to excellent yields, in addition, no side-product formation could be observed during or after the reactions. To well illustrate why the oxidation rate becomes fast firstly and then slows with increased temperatures, five control reactions were carried out and a Fe3+/Fe2+ recycling system was introduced to facilitate the aldehyde oxidation rate. The generality of this method offers the potential for industrial aldehyde-containing waste water treatment.

Failure envelope method is comprehensively used in failure mode prediction of multi-bolt composite joints. The method is based on the assumption that bolt load distribution proportion is constant till failure. However, bearing damage and net-section damage must have some influence on the load distribution and then change structure failure mode. In this paper, tensile experiments of two-bolt and three-bolt joints were conducted to obtain the failure modes and other properties. Three dimensional (3D) finite element models involving damage were constructed, and the results were consistent with experimental data. Then, the models were used to study the effect of damage on failure mode of multi-bolt composite joints. The results show that failure mode prediction with failure envelope method should involve the effect of composite damage. Compared with net-section damage, bearing damage has greater influence on failure mode. Based on conventional failure envelope method, a new evaluation procedure involving damage was proposed.

In this paper, tensile behavior of box-joint structure fabricated by resin transfer moulding (RTM) was investigated. A finite element model (FEM) of the box joint based on cohesive zone model was established to study the joint tensile behavior. Hashin failure criterion and degradation rules were applied to simulate damage modes and to predict failure strength. The FEM results show a good agreement with experimental results. Based on the model, the influences of bolt location and lap length on the joint tensile performances were analyzed. The results show that the delamination between the L-shape part and box-shape parts is the main failure mode. Bolt location affects the damage modes, ultimate load and structure stiffness of the joint, and longer lap length has a tendency to promote ultimate load and structure stiffness.

In this paper, tensile experiments were conducted into single-lap bolted joint between composite laminate and steel with countersunk fastener, and two three-dimensional explicit finite element models were developed using Abaqus/Explicit. Continuum shell elements (SC8R) were used to model in-plane ply failure with built-in damage model while cohesive elements were selected to predict interlaminar damage in model I. 8-node reduced integration solid elements (C3D8R) were chosen to model all the parts with 3D Hashin-type initiation criteria and Camanho degradation law implemented in a VUSDFLD subroutine in model II. The results simulated by both models accurately predicted the elastic loading response and captured overall damage profile compared with the experimental results. The numerical analysis using explicit solver provided acceptable accuracy which highlighted the robust nature and high computational efficiency without convergence issues compared with implicit solver. In addition, the effect of cohesive elements on computational efficiency was investigated to simplify the countersunk joints analysis.

This study further investigated the synergistic effect of micro- and nanofiller doping on matrix material space charges and breakdown characteristics. Accordingly, low-density polyethylene (LDPE) was used as the matrix material, and spherical ZnO particles with sizes of 30 nm and 1 &micro, m were used as additives. Micro-ZnO/LDPE, nano-ZnO/LDPE, and micro-nano-ZnO/LDPE composites were prepared through melt blending. The crystalline morphologies of the composites were observed via polarized light microscopy. The composite crystallinity and melting peak temperature were measured via differential scanning calorimetry, and the micro- and nanoparticle dispersions in the matrix were observed via scanning electron microscopy. The test results showed that the particles were uniformly dispersed in the polyethylene matrix. The filler acted as a heterogeneous nucleation agent in the matrix. The crystal size decreased, thereby increasing the crystal quantity. The doping of inorganic ZnO particles improved the composite crystallinity. The ZnO/LDPE composites were subjected to DC breakdown, space charge, and dielectric spectrum tests. When the crystal arrangement of the sample was loose and its size was large, the breakdown process developed along a shorter path, and the field strength of the composite breakdown decreased. The order of AC and DC breakdown field strengths of the samples was as follows: micro-ZnO/LDPE &lt, pure LDPE &lt, micro-nano-ZnO/LDPE &lt, nano-ZnO/LDPE. The DC and AC breakdown field strengths of the micro- and nano-ZnO/LDPE were 4.7% and 3.2% higher than those of the pure LDPE, respectively. Moreover, the DC and AC breakdown field strengths of the nano-ZnO/LDPE were 11.02% and 15.8% higher than those of the pure LDPE, respectively. The doping of inorganic ZnO particles restrained the space charge accumulation, and the residual charges decreased after short-circuit treatment. The dielectric constant of all nanocomposites was lower than that of LDPE, and the dielectric loss of all composites was higher than that of LDPE.

In this article, low-density polyethylene (LDPE) was used as a matrix polymer, the Micro-ZnO and Nano-ZnO particles were used as the inorganic filler. With the melt blending method, the Nano-ZnO/LDPE(Nano-ZnO particles doping into LDPE), Micro-ZnO/LDPE(Micro-ZnO particles doping into LDPE) and Micro-Nano-ZnO/LDPE (Nano-ZnO and Micro-ZnO particles doping into LDPE in the same time) composites were prepared. Then, the inorganic filler and the composites were dealt with structural characterizations and analysis by Fourier transform infrared (FTIR), Polarization microscope (PLM), and Differential scanning calorimeter (DSC). Besides, these samples were dealt with (alternating current) AC breakdown performance test. The micro-experimental results showed that the Micro-ZnO and Nano-ZnO particles doping reduced the crystal size and increased the crystallization rate. With the change of cell structure, the crystallinity of composites increased. The crystallinity order of different samples was as follows: LDPE &lt, Micro-ZnO/LDPE &lt, Nano-ZnO/LDPE &lt, Micro-Nano-ZnO/LDPE. From the breakdown of the experimental result, with the same mass fraction of the different inorganic doping of particles, the breakdown strength of these composites was different. The Nano-ZnO particle doping could improve the breakdown strength of composites effectively. Among them, the breakdown strength of Nano-ZnO/LDPE and Micro-Nano-ZnO/LDPE were 11% higher and 1.3% lower than that of pure LDPE, respectively. Meanwhile, the breakdown strength of Micro-composite was the lowest but its Weibull shape coefficient was the highest. Therefore, the Micro-ZnO doping was helpful for the Nano-ZnO dispersing in the matrix, which produced the Micro-Nano-synergy effects better.

The melt blending was used to prepare 3 wt% ZnO/low density polyethylene (ZnO/LDPE) nanocomposites in this article. The effect of different inorganic ZnO particles doping on the dielectrical property and crystal habit of LDPE matrix was explored. The nanoparticles size was 9 nm, 30 nm, 100 nm, and 200 nm respectively. Scanning electron microscope (SEM) was used to characterize ZnO nanoparticles whereas differential scanning calorimetry (DSC) was used to make thermal characterization of the samples. Besides, the AC (alternating current), DC (direct current breakdown characteristics and electrical conductivity of the nanocomposites was studied in this article. The experimental results showed that nano-ZnO/LDPE composites had the advantages such as small crystal size, high crystallization rate and crystallinity owing to nano-ZnO particles doping, when doping nano-ZnO particles size was 30 nm, the ZnO/LDPE nanocomposite crystallinity crest value 39.77% appeared. At the mean time, the DC and AC breakdown field strength values of composites were 138.0 kV/mm and 340.4 kV/mm respectively. They were the maximal values which improved 8.24% and 13.85% than LDPE. The AC breakdown field strength of samples decreased with specimen thickness increase. The DC breakdown field strength of LDPE and ZnO/LDPE composites were greater than AC breakdown field strength. From the conductivity experimental result it could be seen that when the experimental temperature and electric field intensity rose, the current density and conductivity of ZnO/LDPE composites increased with the enlargement of ZnO particles size. But the values were less than which of LDPE.

In the present meta-analysis, the efficacy and safety of orlistat in the treatment of non-alcoholic fatty liver (NAFLD) and non-alcoholic steatohepatitis (NASH) were evaluated. PubMed, Embase, the Cochrane Library, Web of Science, and Wan Fang data were searched for controlled trials of orlistat in patients with NAFLD or NASH, published before August 2017. Three randomized controlled trials and four single-arm trials were included. The involved participants with NAFLD or NASH (330 patients) were analyzed for clinical outcomes including alteration in hepatic histological variables and biomarkers of liver function. Improvements were observed in levels of alanine aminotransferase [standard mean difference (SMD)=-1.41; P=0.01], aspartate aminotransferase (SMD=-2.06; P=0.0005), γ-glutamyl transpeptidase (SMD=-1.91; P=0.05), glucose [mean difference (MD)=-0.51; P=0.01], triglycerides (MD=-0.93; P=0.01), homeostasis model assessment of insulin resistance index (MD=-1.05; P=0.04) and body mass index (MD=-1.97; P=0.02), but not in liver fibrosis score (SMD=-0.14; P=0.71). On sub-analyses of the different patient groups, no significant differences were observed in patients with NASH. Taken together, these findings demonstrate that orlistat could serve as a therapeutic drug to improve biochemical indicators of liver damage, but not as first-choice drug for the management of NAFLD or NASH; thus suggesting a novel palliative drug only for the treatment of NAFLD.

The gas and oil exploitation in the South China Sea has gradually accelerated in recent years. Some platforms, such as Liwan3-1, Panyu30-1, etc, are put into use. And there are many deep-sea platforms being built. As known, the marine engineering structures are impacted by complicated sea environment. Especially in typhoon season, the extreme sea states induced by typhoon may lead to structural failures. So probability analysis of the typhoon induced sea states is important to marine engineering designing. The typical method is using some probability distribution models to fit the observed or hind-cast data for calculation of combination of the sea states with different return periods. In this process Gumbel distribution, Frechet distribution, Weibull distribution, Log-normal distribution, P-III distribution are commonly used. There are some problems that need to be solved. Firstly, all of the above models are based on yearly maximum sampling method, so the length and quality of data series will influence the probability analysis obviously. Sometimes the observed data of typhoon induced sea states is not enough for getting the results of high quantiles. Secondly, using different probability models, all of which can pass the hypothetical testing, will get different analysis results. The method differences of parameter estimation will also lead to deviation of probability prediction. In this paper a Double-Layer Nested Probability Model (DLNPM) is proposed based on the Multivariate Compound Extreme Value Distribution (MCEVD) and applied to the long term probability analysis of typhoon induced extreme sea environments of the South China Sea. And the uncertainty analysis caused by different methods and data series is carried out in the study. In the new model typhoon characteristics, including maximum central pressure difference ( $\Delta P$ ), radius of maximum wind speed (Rmax), moving speed of typhoon center ( $Vf$ ), minimum distance between typhoon center and target site ( $\delta$ ), typhoon moving angle ( $\theta$ ) and annual typhoon frequency ( $\lambda$ ), are taken into account. The hind-cast data are calculated based on the joint probability analysis of these typhoon characteristic factors. And the long term probability prediction considering uncertainties are gotten.

Presented here is the first example of synthesizing an array of primary-, secondary-, and tertiary-α-ketoamides with a non-metal catalyst nBu