Search

The technique of loop-mediated isothermal amplification (LAMP) utilizes four (or six) primers targeting six (or eight) regions within a fairly small segment of a genome for amplification, with potential for greater specificity than two primer methods such as polymerase chain reaction. In this study, a set of LAMP primers was designed targeting the 16S–23S ribosomal RNA intergenic spacer region ofStaphylococcus aureus, and tested for sensitivity and specificity in real-time LAMP reactions. Under optimized conditions, the detection limit of our developed assay was 10 fg DNA template ofS. aureusper reaction, with no detectable false-positive response, which was 103-fold more sensitive than previously reported LAMP assay. The assay was shown to detect two strains ofS. aureus, and did not detect 24 non-S. aureusstrains, providing improved specificity over previously reported LAMP assays. [ABSTRACT FROM PUBLISHER]

To predict the motion of a pig to estimate its velocity, position and required driving pressure is essential before pigging. The frictional force between a pig and the pipeline is a key determinant of the prediction accuracy, and a precise evaluation of the frictional force between the pig and the pipeline can enhance the prediction of pig motion. The contact between the pig and the pipeline is a soft interference of rubber and steel, and good performance of nonlinear simulation for evaluating the frictional force has been verified. However, due to some mathematical or technical limitations, the linear elastic behaviour of rubber has sometimes been used to simplify the prediction, greatly affecting the prediction accuracy. To determine the difference between these two cases in this paper, comparisons of linear and nonlinear simulation for predicting the bidirectional pig contact forces are presented. The effects of the elastic module ( E ), interference ( δ ), thickness ( ξ ), and clamping rate ( ζ ) of the sealing disc on the performance of the linear and nonlinear models at different differential pressures are discussed. The results indicate that the contact forces obtained from the linear simulation model are greatly underestimated. The linear simulation model is incapable of predicting the contact force or the frictional force between the pig and the pipeline because the elastic behaviour of the sealing disc is described in the linear approximation. Consequently, the assumption in the pigging simulation that the sealing discs/cups attached on the pig exhibit a linear elastic behaviour lead to improper predictions regarding the pigging time, velocity, driving pressure, and so on. However, the pigging risks and uncertainties can be greatly reduced based on the nonlinear prediction rather than the linear simulation due to the inaccurate simulation results. This study clearly presents the differences between the linear and nonlinear simulations based on the complex behaviour of pig motion in oil and gas pipelines. [ABSTRACT FROM AUTHOR]

The material properties and drill pipe hardbanding performance of PCD reinforced WC matrix composites were investigated in an attempt to understand the relationship between the raw material's properties and its tool performance. The PCD reinforced WC matrix composite consists of two parts: a PCD part and a WC matrix part. The diamond grains and WC grains in different parts are diffusely distributed which make the material combine closely to improve the bonding strength. A height difference is found at the border of these two parts, which is advantageous to form a lubricant film. The drill pipe hardbanding with a composition of PCD reinforced WC matrix composites exhibits the best tool performance under drilling conditions. The excellent anti-friction property and reasonable hardness of this PCD reinforced WC matrix composite are the primary reasons for its enhanced tool performance. The overall results demonstrate that the PCD reinforced WC matrix composites are extremely promising for drill pipe hardbanding applications. [ABSTRACT FROM AUTHOR]

Periodic pigging of oil and gas pipelines for dewatering, cleaning and inspecting is a standard industry procedure. Predicting the motion of a pig to estimate its velocity, position and required driving pressure is essential before pigging. To enhance these predictions, the frictional force between pig and pipeline is a key determinant and insufficient understanding of the frictional force characteristics leads to significant inaccuracies. As the frictional force acting parallel to the pipeline wall plane is a function of contact force in the radial direction, a 2D axisymmetric nonlinear finite element model was proposed to predict the contact force experienced by bi-directional pig by using ANSYS. The impacts of four parameters (including interference, thickness, chamfer dimension and clamping rate of the sealing discs) on the contact force and the deflection angle of the sealing disc are studied at different differential pressures over the pig. Results obtained in this study shows that the thickness of the sealing disc has the greatest impact on contact force of the bi-directional pig, followed by the chamfer dimension, then the clamping rate and finally the interference. A linear relationship between the contact force and the differential pressure can also be observed from the results. Research findings on the characteristic of contact force and deflection angle of sealing disc may provide useful information for the formulation of theoretical or mathematical models to predict the frictional force on the pig, and pigging risks may be efficiently reduced by establish mitigating strategies on the basis of prediction. [ABSTRACT FROM AUTHOR]

The microbubble phenomenon in contact area between soft tribological interfaces in sliding conditions has been directly observed with a custom-built soft tribology instrument. Experimental results show that the formation of microbubble is due to surface instability. The surface instability in soft films arises from a competition between the adhesion forces and the elastic forces. There are two different mechanisms by which the microbubble phenomenon in contact area between soft tribological interfaces in sliding contact. When a shear force is imposed, the microbubble between PU and glass slide is due to surface buckling instability. For the softer rubber, the buckling does not occur in the thin interface layer between PDMS and glass slide and the contact front forms the microbubble edges. Theoretical analyses have been used to discuss the microbubble formation. [ABSTRACT FROM AUTHOR]

The purpose of this study is to develop instant coarse cereal porridge to improve the convenience of coarse cereals by precooking. The effects of cooking time on the rehydration rate and gelatinization degree of coix seeds, red beans, lotus seeds, wheat kernels, and glutinous rice are investigated using the atmospheric pressure precooking process. Cooking time and quality variations of the coarse cereals are analyzed before and after precooking. The optimal cooking times for coix seeds, red beans, lotus seeds, wheat kernels, and glutinous rice under atmospheric pressure cooking are 110, 65, 40, 40, and 35 minutes (abbr. min), respectively. The rehydration rates are 171.5%, 190%, 170.67%, 224%, and 182.67%, respectively, and the gelatinization degrees are 90%, 74.54%, 80.1%, 92.85%, and 96.97%, respectively. The cooking times of pre‐cooked and pressed coix seeds, red beans, lotus seeds, wheat kernels, and glutinous rice are 10, 8, 12, 10, and 6 min, respectively. Compared to coarse cereals without precooking, the cooking time is reduced by 6.6, 6.5, 3, 4, and 2.3 times, respectively. Instant porridge prepared by combining precooked coarse cereals and dried fruits and vegetables can be consumed after soaking in boiling water for 20 min or boiling for 10 min. [ABSTRACT FROM AUTHOR]

Background: Glutamate mediates cerebral ischemia injury via N-methyl-D-aspartate (NMDA) receptor-coupled ion channels, but the activities of glutamate in the heart remain unclear. Aims: To investigate whether or not glutamate contributes to ischemia- and reperfusion (IR)-induced arrhythmias. Methods: Myocardial IR was induced by occlusion of the left anterior descending coronary artery for 30 min and reperfusion for another 30 min. A score system was used to quantify arrhythmias. MK801 (a noncompetitive NMDA receptor antagonist), dihydrokainate (DHK, a glutamate transporter inhibitor) and gabapentin (GBP, a glutamate release inhibitor) were used before ischemia. Serum glutamate levels, Ca2+-ATPase activity, SERCA2a protein expression and myocardial mitochondrial Ca2+ content were assayed. Results: Myocardial IR caused a significant increase in serum glutamate and high incidences of ventricular arrhythmias. GBP and MK801 significantly ameliorated ventricular arrhythmias, improved SERCA2a expression and sarcoplasmic reticulum Ca2+-ATPase activity and reduced Ca2+ accumulated in mitochondria. By contrast, DHK significantly exacerbated reperfusion-related arrhythmias and mitochondrial Ca2+ overload while it decreased SERCA2a expression and activity. Conclusion: This study showed that glutamate mediates reperfusion arrhythmias, and the corresponding mechanism may be associated with Ca2+ overload via the NMDA receptor. Reperfusion arrhythmias may be prevented by inhibiting the release of glutamate or by antagonizing NMDA receptors. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Elastic rubbers are widely used in nature and engineering. In order to better understand soft rough contact under dry and wet conditions during deepwater pipelaying process, various polyurethane (PU) discs both in PU-pipe and PU-steel sliding combinations have been investigated by using self-developed tribometer. The tribological test results show that the friction coefficient can be clearly seen: PU90< PU80 < PU70, under dry conditions. Experimental results also indicate that the two dramatic increases of the frictional coefficient exist in the rough soft PU-pipe contact. The potential influence of asperities and thin liquid film is discussed. [ABSTRACT FROM AUTHOR]

The umbilical cable tensioner is a core component of deep-water oil and gas development, and it can lay and recover the umbilical cables to ensure the transmission of communication signals, electric signals or liquid injection. The displacements of tensioner’s clamping hydraulic cylinders, which are not synchronized as the nonlinear electro-hydraulic control system, results in the occurrence of the crawler mechanism’s stuck phenomenon or cause umbilical cable deformation or even cause damage by the extrusion in the umbilical cable’s clamping process. To ensure synchronous clamping, the structure scheme of umbilical cable tensioner, crawler mechanism, clamping mechanism and the hydraulic system of synchronous clamping control is designed in this study. This article also analyzes the function of structure parameters and hydraulic cylinders’ displacement, speed and acceleration, and builds the synchronous clamping mechanical model to reveal crawler mechanism’ clamping law. The study proposes the control strategy including the fast moving stage, the working stage and the pressuring stage based on proportional–integral–derivative control, and analyzes the characteristics of synchronous clamping control by building the synchronous clamping experimental platform in the lab environment. The experimental data shows that the tensioner’s hydraulic cylinders have excellent synchronous clamping performance and the theoretical analysis is feasible. The research has important guiding significance for the tensioner design, and provides theoretical support for the laying of the deep-sea umbilical cables. [ABSTRACT FROM PUBLISHER]

In this study, a direct observation of the dynamic behaviors of wax-in-oil flow at the rough soft contact was conducted using the optical fluorescent technique. A contact area was produced between a sliding rigid glass plate and a stationary polyurethane elastomer ball. A mixture of wax in oil was used with 90 % silicon oil and 10 % paraffin wax by weight content. It was found that wax particles played an important role at the rough soft contact, which includes the accumulating process from the inlet region of the contact area and passes through at the central region. The behavior of the entrapped wax particles depends on the soft lubrication. Experimental results show that when the speed of sliding friction has a small value, the accumulation and passing through processes of wax particles occur more slowly at the soft contact interface. A major change occurs in the scratch-like lines when the sliding speed increases with rapid change of the conformity between the sliding soft surfaces. [ABSTRACT FROM AUTHOR]

The performance of a Loop-mediated isothermal amplification (LAMP) assay for detecting food-borne pathogen Listeria monocytogenes was presented in this paper. Three pairs of primers were specially designed for recognizing eight distinct sequences of iap gene (P60 extracellular protein, invasion associated protein IAP). Time and temperature conditions for amplification of L. monocytogenes were optimized to be 40 min at 63C. Detection limit level for artificially contaminated raw milk samples by the LAMP assay was 186 cfu/mL corresponding to 8–10 cells per reaction tube, while the detection level by conventional PCR was 1.86 × 105 cfu/mL. Data on natural raw milk samples indicated that the LAMP method was highly specific and sensitive, giving 91.67% concordance with the ISO 10560 reference method for the samples without enrichment and 100% concordance after enrichment. PRACTICAL APPLICATION The LAMP method in this paper provided a powerful tool with the specificity, sensitivity and rapidity for detection of Listeria monocytogenes in raw milk. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing has become one of the most popular techniques for exploring sustainable energy sources. However, friction is associated with the entire fracturing process, presenting significant challenges for development. Facing the huge friction challenges, this review is elaborated in the following three aspects: (1) the fundamentals of hydraulic fracturing, including three aspects of rock fracture mechanism, fracturing fluid, and proppant; (2) the friction challenges in hydraulic fracturing, which mainly exist in friction along the path and friction near wellbore; (3) hydraulic fracturing drag reduction technologies, which are considered proppant segment plug, fracturing fluid viscosity enhancement, and proppant surface modification technologies. Therefore, we should not only understand the challenges in hydraulic fracturing but also know how to mitigate them. Additionally, we call for a strong focus on environmentally friendly, green friction-reducing technologies for oil and gas fields in the future development of the fracturing industry. [ABSTRACT FROM AUTHOR]

Honey adulteration has been on the rise with the increasing demand for high-quality honey, and the authentication of A. cerana honey is a major problem that the current bee industry needs to solve. The aim of this research was to establish the proofreading enzyme-mediated probe cleavage combined with ladder-shape melting temperature isothermal amplification (Proofman-LMTIA) method for the authentication of Apis cerana honey. The LMTIA primers were designed to target the specific 18S rRNA sequence of A. cerana, and the conditions for Proofman-LMTIA amplification were optimized. The specificity and sensitivity of the method were determined and compared with that of the droplet digital polymerase chain reaction (PCR). The optimal temperature of the established Proofman-LMTIA method was 62 °C. The method can specially to detect the A. cerana gene without cross-reactivity with the genomes from other animal and plant species, and the amplification reaction can be finished within 20 min with the sensitivity of 10 pg A. cerana genomic DNA, which was more sensitive than the droplet digital PCR method. The obtained results demonstrate that the established Proofman-LMTIA procedure was specific, sensitive, and rapid, and can be used for authentication of A. cerana honey. [ABSTRACT FROM AUTHOR]

Honey adulteration has been on the rise with the increasing demand for high-quality honey. The ladders-shape melting temperature isothermal amplification (LMTIA) was a newly developed nucleic acid amplification technique, and the aim of this study was to establish a method combining the LMTIA with the proofreading enzyme-mediated probe cleavage (Proof-man probe) for detecting the thaumatin-like protein (TLP) genes of Brassica rapa var. oleifera in honey. The LMTIA primers was selected as a target to be designed, the temperature of the Proof-man LMTIA reaction was optimized, and the specificity, sensitivity, and applicability to the honey samples were determined. The results showed that the Proof-man LMTIA method was highly specific with a detection sensitivity of 30-40 copies genomic DNA/reaction at the optimal temperature of 60°C, and the amplification could be completed within 20 min. This method can detect the adulteration of low-price B. rapa honey into high-price honey. [ABSTRACT FROM AUTHOR]

Background: Recovery of motor dysfunction is important for patients with incomplete cervical spinal cord injury (SCI). To enhance the recovery of muscle strength, both research and treatments mainly focus on injury of upper motor neurons at the direct injury site. However, accumulating evidences have suggested that SCI has a downstream effect on the peripheral nervous system, which may contribute to the poor improvement of the muscle strength after operation. The aim of this study is to investigate the impact of early vs. delayed surgical intervention on the lower motor neurons (LMNs) distal to the injury site in patients with incomplete cervical SCI.Methods: Motor unit number index (MUNIX) was performed on the tibialis anterior (TA), extensor digitorum brevis (EDB) and abductor hallucis (AH) in 47 patients with incomplete cervical SCI (early vs. delayed surgical-treatment: 17 vs. 30) and 34 healthy subjects approximately 12 months after operation. All patients were further assessed by American spinal injury association (ASIA) motor scales and Medical Research Council (MRC) scales.Results: There are no difference of both ASIA motor scores and MRC scales between the patients who accepted early and delayed surgical treatment (P > 0.05). In contrast, the patients undergoing early surgical treatment showed lower MUSIX values in both bilateral EDB and bilateral TA, along with greater MUNIX values in both right-side EDB and right-side TA, compared to the patients who accepted delayed surgical treatment (P < 0.05).Conclusions: Cervical SCI has a negative effect on the LMNs distal to the injury site. Early surgical intervention in Cervical SCI patients may improve the dysfunction of LMNs distal to the injury site, reducing secondary motor neuron loss, and eventually improving clinical prognosis. [ABSTRACT FROM AUTHOR]

The effects of Ni content and maceration metal on the microstructures and mechanical properties of the WC based diamond composites were investigated in an attempt to seek optimal Ni addition concentration and alloy type. The results indicate that the Cu-10Ni-5Mn-29Zn alloy is more suitable to be used as the matrix maceration metal of WC matrix materials. The bending strength of matrix samples increased up to approximately 10% upon 5 wt% Ni addition. The WC based diamond composite with 5 wt% Ni exhibited an optimal overall performance. The strengthening mechanisms of bending strength and diamond retention capabilities were revealed. The good diamond-holding and WC-holding capabilities and the reinforcement of toughness and the plastic of this Cu-10Ni-5Mn-29Zn alloy are the primary reasons for the excellent performance of composites. • The Cu-10Ni-5Mn-29Zn alloy is more suitable to be used as the matrix maceration metal of WC matrix materials. • The WC based diamond composite with 5 wt% Ni exhibited an optimal overall performance. • The primary reasons for the excellent performance of composites was put forward. [ABSTRACT FROM AUTHOR]

NiTi alloy is widely used in extreme working conditions due to its pseudoelasticity, shape memory effect and wear resistance. In this study, the NiTi alloy coating (Ni49.8Ti50.2 (at%)) was fabricated by high-frequency induction heating. The coating was well-formed on the surface of cemented carbide YG8 and converted to crystalline after aging treatment. The results of 70h erosion wear experiments carried on the rotary erosion wear test device showing that the erosion wear amount of the coating was reduced by 93 % compared with that of YG8, resulting from the deformation recovery effect. Moreover, the main erosion wear mechanism of the coating was micro-cutting and ploughing. This study can provide technical support and theoretical basis for preparing of NiTi alloy coating and erosion wear resistance. • The coating was prepared using high-frequency induction heating technology. • The coating has better erosion and wear resistance at different test temperatures. • The ability of recoverable deformation improves the erosion wear resistance of the coating. [ABSTRACT FROM AUTHOR]

With the widespread application of pipelines in engineering, more and more accidents occur because of pipeline leakage. Therefore, it is particularly important to continuously monitor the pipeline pressure. In this study, a non-intrusive and high-sensitivity structure based on FBG (Fiber Bragg grating) sensor is proposed. Firstly, the basic sensing theory of FBG and the state of a pipeline wall under inner pressure are analyzed. Then, structural sensitivity is deduced based on the flexure hinge and mechanical lever. Subsequently, finite element simulation for the whole sensitization structure is carried out, and optimal parameters are determined to obtain the maximum sensitivity. Finally, laboratory experiments are conducted to verify the function of the designed sensitivity structure. The experimental results show a good agreement with the simulation results. In the experiment, it can be found that the designed structure has a strain sensitivity of 9.59 pm/με, which is 11.51 times the pipeline surface strain. Besides, the structure is convenient to operate and has a good applied prospect for the engineering practice. [ABSTRACT FROM AUTHOR]

This study aimed to extend the storage time of fresh-cut lotus roots. A quantitative evaluation was conducted using the grey–correlation analysis method based on the variation–coefficient weight to observe the treatment of acetic acid (0, 2%, and 5%) and ozone (0, 0.3 mg/L, and 0.6 mg/L). Their effects on weight loss rate, browning degree, and the content of reducing sugar, ascorbic acid, and free amino acid were determined. Under varied treatments and storage time, the weight loss rate, browning degree, and content of nutritional components in fresh-cut lotus root differed. Result of the weighted correlation degree showed that for fresh-cut lotus root stored for more than 4 days, 0.3 mg/L ozone could be used as preservative to ensure the storage quality. These findings could provide a scientific basis for using acetic acid and ozone as preservative to extend the storage time of fresh-cut lotus root. [ABSTRACT FROM AUTHOR]

Introduction: Ventricular arrhythmia is commonly provoked by acute cardiac ischemia through sympathetic exaggeration and is often resistant to anti-arrhythmic therapies. Thoracic epidural anesthesia has been reported to terminate fatal ventricular arrhythmia; however, its underlying mechanism is unknown. Methods: Rats were randomly divided into four groups: sham, sham plus bupivacaine, ischemia/reperfusion (IR), and IR plus bupivacaine groups. Bupivacaine (1 mg/mL, 0.05 mL/100 g body weight) was injected intrathecally into the L5–L6 intervertebral space prior to establishing a myocardial IR rat model. Thereafter, cardiac arrhythmia, cardiac function, myocardial injury, and electrical activities of the heart and spinal cord were evaluated. Results: Intrathecal bupivacaine inhibited spinal neural activity, improved heart rate variability, reduced ventricular arrhythmia score, and ameliorated cardiac dysfunction in IR rats. Furthermore, intrathecal bupivacaine attenuated cardiac injury and myocardial apoptosis and regulated cardiomyocyte autophagy and connexin-43 distribution during myocardial IR. Conclusion: Our results indicate that intrathecal bupivacaine blunts spinal neural activity to prevent cardiac arrhythmia and dysfunction induced by IR and that this anti-arrhythmic activity may be associated with regulation of autonomic balance, myocardial apoptosis and autophagy, and cardiac gap junction function. [ABSTRACT FROM AUTHOR]

Doxorubicin (DXB) is one of the most commonly used anticancer agents for treating solid and hematological malignancies; however, DXB-induced cardiorenal toxicity presents a limiting factor to its clinical usefulness in cancer patients. Costunolide (COST) is a naturally occurring sesquiterpene lactone with excellent anti-inflammatory, antioxidant and antiapoptotic properties. This study evaluated the effect of COST on DXB-induced cardiorenal toxicity in rats. Rats were orally treated with COST for 4 weeks and received weekly 5 mg/kg doses of DXB for three weeks. Cardiorenal biochemical biomarkers, lipid profile, oxidative stress, inflammatory cytokines, histological and immunohistochemical analyses were evaluated. DXB-treated rats displayed significantly increased levels of lipid profiles, markers of cardiorenal dysfunction (aspartate aminotransferase, creatine kinase, lactate dehydrogenase, troponin T, blood urea nitrogen, uric acid and creatinine). In addition, DXB markedly upregulated cardiorenal malondialdehyde, tumor necrosis factor-α, interleukin-1β, interleukin-6 levels and decreased glutathione, superoxide dismutase and catalase activities. COST treatment significantly attenuated the aforementioned alterations induced by DXB. Furthermore, histopathological and immunohistochemical analyses revealed that COST ameliorated the histopathological features and reduced p53 and myeloperoxidase expression in the treated rats. These results suggest that COST exhibits cardiorenal protective effects against DXB-induced injury presumably via suppression of oxidative stress, inflammation and apoptosis. [ABSTRACT FROM AUTHOR]

The ladder-shape melting temperature isothermal amplification (LMTIA) is a newly developed technique with advantages of simple mechanism, easy primer design, quick turn-around time, high specificity, high sensitivity and short target sequence compared to the loop-mediated isothermal amplification (LAMP) technique. The objective of this research was to establish the LMTIA assay for detection of chicken in beef. The LMTIA primers targeting the prolactin receptor gene of Gallus gallus were designed, the LMTIA reaction system was optimized, the specificity and the sensitivity of the LMTIA assay were determined. Our results showed that the LMTIA assay was able to specifically detect 100 ng genomic DNA of Gallus gallus, without detecting the 100 ng genomic DNA of Anas platyrhynchos, Felis catus, Sus scrofa, Canis lupus familiaris, Bos taurus or Capra hircus. The sensitivity of the LMTIA assay was 100 pg genomic DNA of G. gallus. Furthermore, the LMTIA assay was able to detect the chicken adulterated in beef with ≥0.1% (w/w) detection limit (LOD). This study holds a promise for facilitation of the surveillance of the commercial adulteration of chicken in beef. [ABSTRACT FROM AUTHOR]

The ladder-shape melting temperature isothermal amplification (LMTIA) is a newly developed technology, and the objective of this study is to establish the LMTIA assay for detection of pork in beef. The LMTIA primers were designed with the prolactin receptor gene of Sus scrofa as the target. The LMTIA reaction system was optimized, and the performance of the LMTIA assay in specificity, sensitivity and detection limit (LOD) was determined. Our results showed that the LMTIA assay was able to specifically detect 10 ng genomic DNA (gDNAs) of Sus scrofa, the sensitivity of the LMTIA assay was 1 ng genomic DNA of Sus scrofa, and the LMTIA assay was able to detect the pork adulterated in beef with 0.1% LOD, which was the same as that of reported PCR assay or LAMP assay. This study holds a promise for facilitating the surveillance of the commercial adulteration of pork in beef. [ABSTRACT FROM AUTHOR]

• LAMP assays were developed for detection of African swine fever (ASF). • The LAMP assays were comparable to the well-established real-time PCR assay. • The LAMP assays are suitable for detection of current ASFV strains in Central Europe, Eastern Europe, and China. African swine fever (ASF) is a fatal disease caused by a virus in domestic pigs. In this study, a real-time loop-mediated isothermal amplification (LAMP) assay and visual LAMP assay were developed for the detection of African swine fever virus (ASFV). LAMP primers targeting the p10 gene of ASFV were designed, the LAMP reaction system was optimized with plasmid pUC57 containing the p10 gene sequence, and the specificities of the real-time LAMP and the visual assays were tested with the DNA or cDNA of pseudorabies virus (PRV), porcine circovirus type 2 (PCV2), classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus (PPV) and ASFV, as well as the plasmid pUC57 containing the p10 gene sequence. The detection limits were determined using a serial dilution of plasmid pUC57 containing the p10 gene sequence. Our results showed that the LAMP assays could accurately and specifically detect ASFV with a detection limit of 30 copies per μ l−1 of pUC57 containing p10 gene sequence. In addition, the LAMP assays were further evaluated using various genotypes of ASFV strains. Furthermore, the LAMP assays are comparable with the well-established real-time PCR assay. This study provides promising solutions for facilitating preliminary and cost-effective surveillance for prevention and control of ASFV. [ABSTRACT FROM AUTHOR]

Purpose: Ocean exploration is of importance and in great demand throughout the world. This results in a huge challenge in tribology in the marine environment. Moreover, polymeric materials with large molecules or macromolecules play an important role in marine equipment. Design/methodology/approach: The tribological performance of sea-water-eroded polyether polyurethane (PU) was systematically studied by using a multi-specimen test machine for different durations from 0 to 60 days. Surface characterization technologies, such as scanning electric microscopy energy dispersive spectroscopy, were used to analyze the PU samples. Findings: It can be found that the COF measured against 316 steel increases with the testing load because of the change of contact areas for the original PU samples. The effect of hydrodynamic lubrication and heat resulted in the decline of the COF with the increase in testing speed. The COF of PU sample immersed for 20 days was the lowest compared with other samples. With the immersion time increased to 60 days, the COF increased first and then decreased. The reduced COF of PU resulted in improved anti-wear performance of the PU sample. Originality/value: These results enhanced the comprehension of the tribological performances of PU immersed in sea-water. [ABSTRACT FROM AUTHOR]

Abstract The friction and casing wear behavior of TSP composites sliding against N80 casing steels and lubricated by drilling fluids were investigated. It was found that the water-based drilling fluid reduced friction coefficient and casing wear effectively. The surface lubricating films with iron oxide grains formed on the surface of casings are all observed for the three hardbandings, while the discontinuous lubrication film of N3 alloy might account for the higher casing wear therewith. The lowest friction coefficient and casing wear was recorded for TSP composite under load of 10–130 N. This is dependent on the adsorbed lubricating liquid on the rubbing surface and the formation of height difference between the TSP part and the WC matrix part. Highlights • The water-based drilling fluid reduced friction coefficient and casing wear effectively. • The tool performace of three hardbanding rings can be ranked as TSP composite>A3 alloy>N3 alloy. • The surface lubricating films with iron oxide grains formed on the surface of casings are observed. • The TSP composite exhibited excellent performance, mainly because of the more lubricant adsorbed on the rubbing surface. [ABSTRACT FROM AUTHOR]

Abstract In order to save land resources for pipeline construction and reduce maintenance costs, a method of parallel laying pipeline has been adopted. The safety spacing was the primary problem to ensure the security of pipeline laying and operating. A numerical simulation method of buried parallel gas pipelines leakage-induced explosion based on TNT equivalent was presented. According to the combustible gas explosion theory, the damage law of shock waves impact on the parallel pipeline was analyzed. The maximum displacement with different parallel space and different thickness were simulated and discussed. Ultimately, the degree of risk of buried pipelines parallel spacing was analyzed and the safety spacing was determined. It provided guidance for the construction and operation of buried parallel gas pipelines. Highlights • Numerical simulation of buried parallel natural gas pipeline explosive was carried out based on TNT equivalent method. • The fracture failure position was perpendicular to the maximum deformation position when the distance was less than 3 m. • The maximum deformation position was gradually transferred to the top of pipeline coinciding with fracture failure position. • The safety distance between two buried parallel pipelines was more than 8 m for pipeline thickness 22 mm. [ABSTRACT FROM AUTHOR]

PAH/Au/PAH/PAA film was prepared by the layer-by-layer (LbL) method. AFM and micro-tribometer were used to evaluate the frictional and wear behaviors of the film. The result indicated that heat treatment can improve the bonding force of the film because of the conversion from electrostatic interaction to covalent bond. Which greatly enhanced the film's anti-wear life. However, the film surface's roughness increases dramatically and uniformity decreases with longer heating time. Which would influence the friction and wear performance of the film. Thus, the heating time is a critical parameter in the prospect of improving the film layers bonding strength, consequently enhancing the wear-resistant of the polyelectrolyte/Au nanoparticles multilayer film. [ABSTRACT FROM AUTHOR]