The tribological properties of zinc borate ultrafine powder as a lubricant additive in sunflower oil

This paper presents an investigation on the tribological properties of zinc borate ultrafine powder employed as a lubricant additive in sunflower oil. The stable dispersions of 0.5 wt%, 1 wt% and 2 wt% zinc borate ultrafine powder in sunflower oil were achieved by using an ultrasonic homogeniser. Both a 4-ball tester and a pin-on-disc tester were employed to evaluate the anti-wear and friction reduction capabilities of zinc borate ultrafine powder. Tribo-films with dark colour were generated on the worn surfaces and showed a good contrast with the substrate. The worn surface with different morphologies reflected as the colour alterations on the worn surface were observed when different lubricants were applied. The morphology and elemental analysis of the worn surfaces were studied using atomic force microscopy (AFM) and scanning electronic microscopy (SEM). Mechanical properties of the tribo-films and substrates were studied with a nano-indentation tester. Test results suggest that tribo-films generated on the worn surface have a relatively low hardness compared with the steel substrate. The substrates on the worn surfaces lubricated in sunflower oil with the powder demonstrated higher hardness than that of the substrate lubricated with pure sunflower oil due to the possible tribo-chemical reaction between the zinc borate additive and substrate. The combination of sunflower oil with 0.5% zinc borate ultrafine powder has delivered the most balanced performance in friction and wear reduction. This study has demonstrated the possibility of application of this industrially applicable solid lubricant additive (zinc borate) with a decomposable vegetable based lubricant oil.Peer reviewedFinal Accepted Versio

An hp hp -version spectral collocation method for fractional Volterra integro-differential equations with weakly singular kernels

We present a multi-step spectral collocation method to solve Caputo-type fractional integro-differential equations (FIDEs) involving weakly singular kernels. We reformulate the problem as the second type Volterra integral equation (VIE) with two different weakly singular kernels. Based on these integral equations, we construct a multi-step Legendre-Gauss spectral collocation scheme for the problem. The $hp$-version convergence is established rigorously. To demonstrate the effectiveness of the suggested method and the validity of the theoretical results, the results of some numerical experiments are presented

Radiomics Signature on Computed Tomography Imaging: Association With Lymph Node Metastasis in Patients With Gastric Cancer

Background: To evaluate whether radiomic feature-based computed tomography (CT) imaging signatures allow prediction of lymph node (LN) metastasis in gastric cancer (GC) and to develop a preoperative nomogram for predicting LN status.Methods: We retrospectively analyzed radiomics features of CT images in 1,689 consecutive patients from three cancer centers. The prediction model was developed in the training cohort and validated in internal and external validation cohorts. Lasso regression model was utilized to select features and build radiomics signature. Multivariable logistic regression analysis was utilized to develop the model. We integrated the radiomics signature, clinical T and N stage, and other independent clinicopathologic variables, and this was presented as a radiomics nomogram. The performance of the nomogram was assessed with calibration, discrimination, and clinical usefulness.Results: The radiomics signature was significantly associated with pathological LN stage in training and validation cohorts. Multivariable logistic analysis found the radiomics signature was an independent predictor of LN metastasis. The nomogram showed good discrimination and calibration.Conclusions: The newly developed radiomic signature was a powerful predictor of LN metastasis and the radiomics nomogram could facilitate the preoperative individualized prediction of LN status

Myosin Light Chain Kinase Mediates Intestinal Barrier Disruption following Burn Injury

Background: Severe burn injury results in the loss of intestinal barrier function, however, the underlying mechanism remains unclear. Myosin light chain (MLC) phosphorylation mediated by MLC kinase (MLCK) is critical to the pathophysiological regulation of intestinal barrier function. We hypothesized that the MLCK-dependent MLC phosphorylation mediates the regulation of intestinal barrier function following burn injury, and that MLCK inhibition attenuates the burn-induced intestinal barrier disfunction. Methodology/Principal Findings: Male balb/c mice were assigned randomly to either sham burn (control) or 30 % total body surface area (TBSA) full thickness burn without or with intraperitoneal injection of ML-9 (2 mg/kg), an MLCK inhibitor. In vivo intestinal permeability to fluorescein isothiocyanate (FITC)-dextran was measured. Intestinal mucosa injury was assessed histologically. Tight junction proteins ZO-1, occludin and claudin-1 was analyzed by immunofluorescent assay. Expression of MLCK and phosphorylated MLC in ileal mucosa was assessed by Western blot. Intestinal permeability was increased significantly after burn injury, which was accompanied by mucosa injury, tight junction protein alterations, and increase of both MLCK and MLC phosphorylation. Treatment with ML-9 attenuated the burn-caused increase of intestinal permeability, mucosa injury, tight junction protein alterations, and decreased MLC phosphorylation, but not MLCK expression

A Study of Tribological Properties of Water-Based Ceria Nanofluids

This is an Accepted Manuscript of an article published by Taylor & Francis in Tribology Transactions on 10 January 2013, available online: http://www.tandfonline.com/doi/abs/10.1080/10402004.2012.748948.This paper presents an investigation on the potential tribological properties of the water-based cerium dioxide nanofluids. The nanofluids with different nanoparticle concentrations were prepared in a materials laboratory. A stable dispersion of nanoparticles in the fluids was achieved with an appropriate percentage of surfactant sorbitan monostearate. The stability of particle dispersion was studied using a Zeta-potential measuring device. Additive conglomerate size in the nanofluids was measured using Dynamic Light Scattering (DLS) device. It has been observed that the dispersibility of nanoparticles played an important role in the frictional properties of the nanofluids. The tribological properties of the water-based nanofluids were evaluated using a Pin-on-disc tester under different loading conditions. A significant improvement on tribological properties of the water-based cerium dioxide nanofluids was observed. The worn surfaces of the contact elements were characterised using SEM and a Nano-tester. According to the test results, the significant reductions of the friction coefficient and the anti-wear property of water-based cerium dioxide nanofluids are attributed to the deposition of nanoparticles on worn contact surfaces.Peer reviewe

The preparation and tribological properties of surface modified zinc borate ultrafine powder as a lubricant additive in liquid paraffin

This paper investigates the effects of surface modification of zinc borate ultrafine powders (ZB UFPs) on their tribological properties as lubricant additives in liquid paraffin (LP). ZB UFPs were successfully modified by hexadecyltrimethoxysilane (HDTMOS) and oleic acid (OA). It is evident that HDTMOS modified zinc borate ultrafine powder (HDTMOS-ZB UFP) delivered a small conglomerate size, good stability in the organic solvent and sound anti-wear property. It has been observed that a continuous and tenacious tribo-film on the worn surface generated from HDTMOS modified ZB UFP as a lubricant additive in LP plays an important role in the outstanding anti-wear property. It is suggested that HDTMOS modified ZB UFP as a lubricant additive in LP has a great potential.Peer reviewedSubmitted Versio

Expression and prognostic value of miR-486-5p in patients with gastric adenocarcinoma.

MicroRNA (miR)-486-5p expression is often reduced in human cancers. However, its expression in gastric carcinoma and its relation to clinicopathological features and prognosis are unclear. Tissue microarrays were constructed from 84 patients with gastric adenocarcinoma (GC) who were undergoing radical resection. miR-486-5p expression was detected by miRNA-locked nucleic acid in situ hybridization, and its correlations with clinicopathological features and overall survival were analyzed. Bioinformatic studies predict that fibroblast growth factor 9 (FGF9) is a potential target gene of miR-486-5p. miR-486-5p was mainly located in the cytoplasm of GC cells and neighboring normal tissues. Compared with paracancerous normal tissue, miR-486-5p expression was decreased in 63.1% (53/84) of the GC samples, increased in 32.1% (27/84) and unchanged in 4.8% (4/84). FGF9 expression was decreased in 69.0% (58/84) of GC samples and increased in 31.0% (26/84) compared with normal paracancerous tissues using immunohistochemical analysis. Low or unchanged miR-486-5p expression (P = 0.002), tumor stage (P = 0.001), tumor status (P = 0.001), node status (P = 0.001), tumor size (P = 0.004), and depth of tumor invasion (P = 0.013) were significant negative prognostic predictors for overall survival in patients with GC. After stratification according to American Joint Committee on Cancer (AJCC) stage, low/unchanged miR-486-5p expression remained a significant predictor of poor survival in stage II (P = 0.024) and stage III (P = 0.003). Cox regression analysis identified the following predictors of poor prognosis: tumor status (hazard ratio [HR], 7.19; 95% confidence interval [CI], 1.75-29.6; P = 0.006), stage (HR, 2.62; 95%CI, 1.50-4.59; P = 0.001), lymph node metastasis (HR, 2.52; 95% CI, 1.27-4.99; P = 0.008), low/unchanged miR-486-5p (HR, 2.47; 95% CI, 1.35-4.52; P = 0.003), high level of FGF9 (HR, 2.41; 95% CI, 1.42-4.09; P = 0.001) and tumor size (HR, 2.50; 95% CI, 1.30-4.82; P = 0.006). Low or unchanged expression of miR-486-5p compared with neighboring normal tissues was associated with a poor prognosis, while high expression was associated with a good prognosis in GC. miR-486-5p may thus be useful for evaluating prognosis and may provide a novel target treatment in patients with GC

Hierarchical-fuzzy allocation and multi-parameter adjustment prediction for industrial loading optimisation

Conventional manual-programmable logic controller systems have confronted the problems of the unbalance load and the unreasonable bins allocation in industrial loading field. Furthermore, various optimisation models with multi-agent systems have been proposed for the single-layer scheduling and communicating, which results in either a high time cost or a difficult multi-target regression. In this paper, we propose a hierarchical-fuzzy bins allocation method and a multi-parameter adjustment values prediction model in the multi-agent collaborative control system. The method intuitively achieves topgallant and hierarchical bins allocation by different fuzzy rule bases. The multi-parameter adjustment values prediction model utilising parallel-multi LSTM(PM-LSTM) is located on the accurate multi-parameter prediction. First, new loading reference standards and an abnormal data procession method are adopted for the dataset collection. Second, the LSTM-1 is used to extract the time-series features in the loading process. Third, a two-dimensional and reconstructed matrix integrates comprehensive features with the feature crossover method. The matrix will be used as inputs to predict the adjustment value of multi parameters by the LSTM-2. Finally, the relationship model among multi parameter values is built and fitted. Experiment results show better effects for the reasonable bins allocation and balanced industrial loading

High-Performance Polyimide Filaments and Composites Improved by O2 Plasma Treatment

Interface issues urgently need to be addressed in high-performance fiber reinforced composites. In this study, different periods of O2 plasma treatment are proposed to modify twist-free polyimide (PI) filaments to improve hydrophilicity and mechanical and interfacial properties. Feeding O2 produces chemically active particles to modify the filament surface via chemical reactions and physical etching. According to the X-ray photoelectron spectroscopy (XPS) results, the PI filaments exhibit an 87.16% increase in O/C atomic ratio and a 135.71% increase in the C–O functional group after 180 s O2 plasma treatment. The atomic force microscope (AFM) results show that the root mean square roughness (Rq) of the treated PI filaments increases by 105.34%, from 38.41 to 78.87 nm. Owing to the increased surface oxygenic functional groups and roughness after O2 plasma treatment, the contact angle between treated PI filaments and water reduces drastically from the pristine state of 105.08° to 56.15°. The O2 plasma treated PI filaments also demonstrate better mechanical properties than the pristine PI filaments. Moreover, after O2 plasma treatment, the adhesion between PI filaments and poly(amic acid) (PAA) is enhanced, and the tensile strength of the polyimide/poly(amic acid) (PI/PAA) self-reinforced composites increases from 136 to 234 MPa, even causing the failure mode of the composite changes from adhesive failure to partly cohesive failure