Validation of a New Prognostic Score in Patients with Ovarian Adenocarcinoma

Background and Objectives: This study aimed to assess the impact of clinical prognostic factors and propose a prognostic score that aids the clinician’s decision in estimating the risk for patients in clinical practice. Materials and Methods: The study included 195 patients diagnosed with ovarian adenocarcinoma. The therapeutic strategy involved multidisciplinary decisions: surgery followed by adjuvant chemotherapy (80%), neoadjuvant chemotherapy followed by surgery (16.4%), and only chemotherapy in selected cases (3.6%). Results: After a median follow-up of 68 months, in terms of progression-free survival (PFS) and overall survival (OS), Eastern Cooperative Oncology Group (ECOG) performance status of 1 and 2 vs. 0 (hazard ratio—HR = 2.71, 95% confidence interval—CI, 1.96–3.73, p < 0.001 for PFS and HR = 3.19, 95%CI, 2.20–4.64, p < 0.001 for OS), menopausal vs. premenopausal status (HR = 2.02, 95%CI, 1.35–3,0 p < 0.001 and HR = 2.25, 95%CI = 1.41–3.59, p < 0.001), ascites (HR = 1.95, 95%CI 1.35–2.80, p = 0.03, HR = 2.31, 95%CI = 1.52–3.5, p < 0.007), residual disease (HR = 5.12, 95%CI 3.43–7.65, p < 0.0001 and HR = 4.07, 95%CI = 2.59–6.39, p < 0.0001), and thrombocytosis (HR = 2.48 95%CI = 1.72–3.58, p < 0.0001, HR = 3.33, 95%CI = 2.16–5.13, p < 0.0001) were associated with a poor prognosis. An original prognostic score including these characteristics was validated using receiver operating characteristic (ROC) curves (area under the curve—AUC = 0.799 for PFS and AUC = 0.726 for OS, p < 0.001). The median PFS for patients with none, one, two, three, or four (or more) prognostic factors was not reached, 70, 36, 20, and 12 months, respectively. The corresponding median overall survival (OS) was not reached, 108, 77, 60, and 34 months, respectively. Conclusions: Several negative prognostic factors were identified: ECOG performance status ≥ 1, the presence of ascites and residual disease after surgery, thrombocytosis, and menopausal status. These led to the development of an original prognostic score that can be helpful in clinical practice

Investigation of monitoring techniques for the detection of tool/workpiece malfunctions in milling of heat resistant alloys

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Investigation of monitoring techniques for the detection of tool/workpiece malfunctions in milling of heat resistant alloys

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Rules and Discretion in Monetary Policy: Is the Response of the Stock Market Rational?

We investigate the effects of the monetary policy conduct on the domestic capital market for a sample of developed countries where the capital market plays a significant role in the economy. We break down the policy rate innovations in rules-based and discretionary components in order to determine the degree of prudentiality in the monetary policy conduct and we study their accounts with respect to capital market rationality. The rules-based component is determined using an interpolated vanilla Taylor-rule policy rate at the event date and the discretionary component is obtained by subtracting the rules-based rate from the target monetary policy rate innovation. Using an event study approach, we analyze the impact of monetary policy components on the returns of the stock market and we determine that the conduct of the monetary policy can cause irrational responses of the capital market. More than that, we show, for the analyzed countries, that if the general level of discretion in the monetary policy is high the response of the stock market becomes increasingly erratic, indicating that forward guidance may help reduce uncertainty on capital markets

Study of interactions between close HVDC links inserted in an AC grid: A mixed nonlinear and modal analysis approach

International audienceThis paper focuses on interaction between two closed-connected high-voltage DC (HVDC) lines. This interaction is studied by employing high-fidelity nonlinear modeling in MATLAB R /Simulink R software environment. In order to describe the mechanism behind the HVDCs interaction, both nonlinear time-domain simulations and modal analysis of the coupled HVDC links, have been performed. System small-signal stability has been assessed and the path of interactions has been identified by computing the participations of various states in the oscillatory modes; this sets the preliminaries for a global, grid-oriented HVDCs control design approach. After the detailed analysis of newly-identified coupling oscillations , the minimal modeling requirements to put them into evidence have also been studied; this significantly facilitates the analysis in a realistic large-scale grid context

Effects of surface roughness on bonding behavior of cold spray ti6al4v coatings

In this study, a penitential additive manufacturing method-cold spray was used to deposit Ti6Al4V powders onto Ti6Al4V substrates with different surface roughness by using a high pressure cold spray system. The coating quality was good with limited porosity and without phase transition. Interface bonding behavior between coating and substrate was studied, which indicated that smoother substrate surface would increase the bonding strength. Bending test showed that all the coated samples started to delaminate before substrate failure and smoother surface samples could resist higher stress than the rougher surface samples

Evaluation of cold sprayed graphene nanoplates–Inconel 718 composite coatings

Graphene nanoplates (GNPs)–Inconel 718 (IN718) composite coatings were fabricated via high pressure cold spray technique with varying contents of GNPs mixed with IN718 powder. The microstructure, mechanical properties and tribological behavior of the composite coatings were systemically investigated. IN718-GNPs composite coatings could be effectively formed with the incorporation of 0.15 wt% GNPs that were uniformly distributed within the cold sprayed coatings. The deposition efficiency tended to decrease with increasing GNPs content. Following this lead, the surface roughness of the as-sprayed IN718-GNPs composite coatings was found to be related to the addition of GNPs. The surface roughness gradually increased with increasing GNPs content and the composite coating surfaces had plateau-like and crater-like features. TEM lamellae were extracted from the IN718-IN718 and IN718-GNPs interfaces of the composite coatings by focused ion beam milling. The interface between the GNPs and the IN718 matrix was clean and well bonded, illustrating a mechanical bonding. Most importantly, we found that the IN718-GNPs composite coatings provided appreciable reductions in coefficient of friction and wear rate compared to the pure IN718 coatings due to the GNPs’ exfoliated surfaces and intrinsically high lubricating characteristics. Hence, the IN718-GNPs composite coatings could be excellent candidates for low friction and high wear-resistance applications

Adhesion, tribological and corrosion properties of cold-sprayed CoCrMo and Ti6Al4V coatings on 6061-T651 Al alloy

In this study, CoCrMo and Ti6Al4V coatings were deposited on 6061-T651 aluminum alloy substrates via a high pressure cold spray process. Adhesion, tribological and corrosion properties of the CoCrMo and Ti6Al4V coatings were systematically investigated. The CoCrMo and Ti6Al4V coatings had good quality with low porosity levels and high hardnesses. X-ray diffraction patterns showed that there were no phase change and oxidation for the CoCrMo and Ti6Al4V coatings with reference to the CoCrMo and Ti6Al4V powder feedstocks. The shear bonding tests indicated good adhesion quality between the coatings and substrates. The tribological results showed that the CoCrMo coatings significantly enhanced the wear resistance of the Al alloy substrates. The corrosion results showed that the CoCrMo and Ti6Al4V coatings had higher anti-corrosion performances compared to the bare Al alloy substrates in a 3.5 wt% NaCl solution as the corrosion current densities for the CoCrMo and Ti6Al4V coated samples were substantially reduced

An investigation into microstructure, tribological and mechanical properties of cold sprayed Inconel 625 coatings

In this study, Inconel 625 coatings were successfully deposited on 6061 aluminum alloy using a high-pressure cold spray process. The microstructure, mechanical and tribological properties of the coatings were systematically studied. The cold sprayed Inconel 625 coatings had a low porosity level due to the severe plastic deformation of the splats. EBSD analyses revealed that grain refinement occurred within the coatings and substrates (near the substrate-coating interface), which could be attributed to strain accumulation and fragmentation process. Good adhesion strength of above 57.0 MPa was achieved between the coatings and substrates. Nano-hardness and micro-hardness values were higher than those of bulk Inconel 625 and were uniform along the thickness of the coatings. The effects of normal load and sliding velocity on the tribological properties of cold sprayed Inconel 625 coatings were investigated by sliding wear tests. The wear results demonstrated that both increased sliding velocity and normal load led to higher specific wear rates, which could result from the combined effects of tribo-film delamination, adhesive wear, abrasive wear, and thermal softening. Lower coefficients of friction of the coatings measured under 5 N compared to those measured under 2 N with the same sliding velocity could be explained by transition of wear mechanisms as well as larger coverage of tribo-film on the wear tracks