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Abstract Background There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor prognosis in patients with advanced cancers. We evaluated the relationships between clinical status, laboratory factors and progression free survival (PFS), and overall survival (OS) in patients with recurrent or metastatic gastric cancer receiving first-line palliative chemotherapy. Methods We reviewed 402 patients with advanced gastric adenocarcinoma who received first-line palliative chemotherapy from June 2004 and December 2009. Various chemotherapy regimens were used. Eastern Cooperative Oncology Group performance status (ECOG PS), C-reactive protein (CRP), albumin, Glasgow prognostic score (GPS), and clinical factors were recorded immediately prior to first-line chemotherapy. Patients with both an elevated CRP (>1.0 mg/dL) and hypoalbuminemia ( Results According to multivariate analysis, the factors independently associated with PFS were ECOG PS (HR 1.37, 95% CI 1.02-1.84, P = 0.035), bone metastasis (HR 1.74, 95% CI 1.14-2.65, P = 0.009), and CRP elevation (HR 1.64, 95% CI 1.28-2.09, P = 0.001). The factors independently associated with OS were ECOG PS (HR 1.33, 95% CI 1.01-1.76, P = 0.037), bone metastasis (HR 1.61, 95% CI 1.08-2.39, P = 0.017), and GPS ≥ 1 (HR 1.76, 95% CI 1.41-2.19, P = 0.001). Conclusions The results of this study showed that the presence of a systemic inflammatory response as evidenced by the CRP, GPS was significantly associated with shorter PFS and OS in patients with recurrent or metastatic gastric cancer receiving first-line palliative chemotherapy. Bone metastasis and GPS were very useful indicator for survival in patients with recurrent or metastatic gastric cancer receiving palliative chemotherapy.

Epoxy is a polymeric material that is widely used in various fields as an adhesive, coating, and bulk material due to its outstanding properties. Many research studies on reinforced polymers have been conducted by adding micro/nanoparticles or fibers to attain better tribological properties. However, the tribological properties of patterning on the epoxy surface are relatively obscure. In this study, friction and wear properties of flat and V-groove patterned epoxy specimens were analyzed in dry and water lubricated sliding conditions to assess the effectiveness of the surface pattern in reducing friction and wear. It was found that under low applied force conditions in which the V grooves remained almost intact, the surface pattern contributed to decreasing the friction coefficient as much as 0.12 and increasing the stability of frictional behavior in dry sliding condition. This outcome was attributed to the ability of the grooves to trap wear debris inside the cavities. However, under water lubrication with polytetrafluoroethylene (PTFE) particles used as additives, the V-groove specimens were less effective in reducing friction due to the relatively small contact area. As the contact area increased, the effect of water lubrication with PTFE particles in reducing friction could be enhanced. These results are expected to serve as a fundamental basis for designing and fabricating the surface of polymeric components for tribological applications in dry and lubricated conditions. [ABSTRACT FROM AUTHOR]

This work focuses on the mechanism of surface damage at the head/disk interface of a hard disk drive (HDD) during contact. Tribological experiments were performed using a contact-start-stop (CSS) tester as well as a drag tester. The results of both CSS and drag tests showed that the surface damage of the slider surface occurred by abrasive wear and adhesion. Wear particles tend to pile up along the front edges and the boundary of the air bearing surface of the slider. As for the disk surface, evidence of mild burnishing wear could be found, and its surface roughness decreased with increasing number of contact cycles. It is anticipated that the results of this work will serve as the basis for developing schemes for improving reliability in the head/disk system that experiences significant contact. Index Terms - Contact-Start-Stop test, drag test, head/disk interface, tribology.

Tribological optimization of the head/disk interface is crucial to attain reliable performance of hard disk drives. As the flying height of the slider above the disk continues to decrease with increase in recording density, the concern for surface damage is greater than ever before. In this work a novel method to reduce debris contamination by way of trapping the particles in micro-grooves on the slider surface to protect the head is proposed. Tests performed with dummy sliders with several types of strategically designed micro-grooves show that the grooves are effective in removing the wear debris at the slider/disk interface. Furthermore, concept for stiction-free slider design has been investigated. Micro-bumps were fabricated on a slider surface in order to reduce stiction. Preliminary tests show that compared with conventional sliders, these sliders result in significantly lower stiction during contact-start-stop tests performed on the data zone of a magnetic disk. The concepts proposed in this work may be utilized in the design of future sliders for low flying heads on super-smooth disks. Index Terms--Contamination, drag test, head/disk interface, wear debris.

Head contamination is a serious problem that must be avoided for high reliability. It has been previously reported that the wear debris contamination behavior of head/slider varies as the flying height of the slider is lowered. The emphasis of this paper is on identifying the trend of wear debris contamination on the air bearing surface of a slider due to contact with the disk. The surface damage effect of the slider was accelerated by conducting sliding tests in drag conditions. It was found that for a wide range of effective slider load, the wear debris tend to accumulate near the edges of the air bearing features on the slider surface. As a means to prevent the head from being contaminated by wear debris, the use of micro-grooved surface is proposed. The effectiveness of micro-grooves on a silicon surface in trapping wear particles is demonstrated. Hence, grooves may be used strategically on the slider air bearing surface to develop contamination-free sliders. Index Terms--Contamination, drag test, head/disk interface, wear debris.

60 years ago, in 1958, Ernest Rabinowicz published a 5 page paper titled “The effect of size on the looseness of wear fragments” where he suggested a criterion determining the minimum size of wear particles. The criterion of Rabinowicz is based on the consideration of the interplay of elastic energy stored in “asperities” and the work of separation needed for detaching a wear particle. He was probably the first researcher who explicitly emphasized the role of adhesion in friction and wear. In a recent paper in Nature Communications, Aghababaei, Warner and Molinari confirmed the criterion of Rabinowicz by means of quasi-molecular dynamics and illustrated the exact mechanism of the transition from plastic smoothing to formation of wear debris. This latter paper promoted the criterion of Rabinowicz to a new paradigm for current studies of adhesive wear. The size arguments of Rabinowicz can be applied in the same form also to many other problems, such as brittle-ductile transition during indentation, cutting of materials or ultimate strength of nano-composites. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE) matrix with inherently low friction was prepared in the form of a coating and reinforced with carbon nanotubes (CNTs) to enhance its wear resistance. PTFE–CNT composite coatings with various CNT contents were deposited on silicon (100) substrates by spin coating followed by a heat treatment process. The effects of cooling rate during the heat treatment process on the morphology, mechanical properties as well as friction and wear behavior of the coatings were investigated under different loading conditions. It was revealed that the slow‐cooled PTFE–CNT composite coating containing 1 wt% and 5 wt% CNT had the highest wear resistance with respect to the applied normal load. The overall experimental results demonstrated that, in comparison to pure PTFE coating, the friction and wear behavior of PTFE–CNT composite coatings could be improved by incorporating an optimum amount of CNT in the PTFE matrix and performing the heat treatment under a specified condition. POLYM. COMPOS., 39:E710–E722, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Backgrounds: Fisetin (tetrahydroxyflavone), a natural plant component, is known to have different properties including, direct radical scavenger, anti-inflammation, and cell survival.Methods: We investigated whether fisetin can protect cardiomyocytes against H2O2-induced apoptosis that is relevant to cardiovascular disease risks using cell viability test, ROS measurement, and Western blotting.Results: Fisetin decreased apoptotic cell death and intracellular reactive oxygen species (ROS), while enhancing the expression of Cu/Zn-superoxide dismutase (SOD) as well as phosphorylation of Akt and extracellular regulated kinase (ERK) 1/2. In particular, fisetin significantly decreased apoptosis through inhibition of cleaved caspase-3 and Bax expression and by enhancing the expression of anti-apoptotic enzyme as well as Bcl-2 in H2O2-stimulated H9c2 cells. However, the expression of heme oxygenase, catalase, and Mn-SOD was not altered by fisetin in these conditions.Conclusion: Taken together, these data suggest that the potential cardioprotective effect of fisetin may involve Cu/Zn-SOD-mediated activation of Bcl-2 through the Akt and ERK1/2 pathways. [ABSTRACT FROM AUTHOR]