Microstructure evolution modeling of square-diamond pass hot bar rolling of AISI 4135 steel

In this study, kinetics of the static (SRX) and metadynamic recrystallization (MDRX) of AISI4135 steel was investigated using hot torsion tests. Continuous torsion tests were carried out to determine the critical strain for dynamic recrystallization (DRX). The times for 50% recrystallization of SRX and MDRX were determined, respectively, by means of interrupted torsion tests. Furthermore, austenite grain size (AGS) evolution due to recrystallization (RX) was measured by optical microscopy. With the help of the evolution model established, the AGS for hot bar rolling of AISI4135 steel was predicted numerically. The predicted AGS values were compared with the results using the other model available in the literature and experimental results to verify its validity. Then, numerical predictions depending on various process parameters such as interpass time, temperature, and roll speed were made to investigate the effect of these parameters on AGS distributions for square-diamond pass rolling. Such numerical results were found to be beneficial in understanding the effect of processing conditions on the microstructure evolution better and control the rolling processes more accurately.<br /

Safety and Efficacy of Second-Generation Everolimus-Eluting Xience V Stents Versus Zotarolimus-Eluting Resolute Stents in Real-World Practice Patient-Related and Stent-Related Outcomes From the Multicenter Prospective EXCELLENT and RESOLUTE-Korea Registries

ObjectivesThis study sought to compare the safety and efficacy of the Xience V/Promus everolimus-eluting stent (EES) (Abbott Vascular, Temecula, California) with the Endeavor Resolute zotarolimus-eluting stent (ZES-R) (Medtronic Cardiovascular, Santa Rosa, California) in “all-comer” cohorts.BackgroundOnly 2 randomized controlled trials have compared these stents.MethodsThe EXCELLENT (Efficacy of Xience/Promus Versus Cypher to Reduce Late Loss After Stenting) and RESOLUTE-Korea registries prospectively enrolled 3,056 patients treated with the EES and 1,998 patients treated with the ZES-R, respectively, without exclusions. Stent-related composite outcomes (target lesion failure [TLF]) and patient-related composite outcomes were compared in crude and propensity score-matched analyses.ResultsOf 5,054 patients, 3,830 (75.8%) had off-label indication (2,217 treated with EES and 1,613 treated with ZES-R). The stent-related outcome (82 [2.7%] vs. 58 [2.9%], p = 0.662) and the patient-related outcome (225 [7.4%] vs. 153 [7.7%], p = 0.702) did not differ between EES and ZES-R, respectively, at 1 year, which was corroborated by similar results from the propensity score-matched cohort. The rate of definite or probable stent thrombosis (18 [0.6%] vs. 7 [0.4%], p = 0.306) also was similar. In multivariate analysis, off-label indication was the strongest predictor of TLF (adjusted hazard ratio: 2.882; 95% confidence interval: 1.226 to 6.779; p = 0.015).ConclusionsIn this robust real-world registry with unrestricted use of EES and ZES-R, both stents showed comparable safety and efficacy at 1-year follow-up. Overall incidences of TLF and definite stent thrombosis were low, even in the patients with off-label indication, suggesting excellent safety and efficacy of both types of second-generation drug-eluting stents

The effect of alkaline phosphatase and intrahepatic metastases in large hepatocellular carcinoma

BACKGROUND: Hepatectomy is the standard treatment for HCC. However, large HCC poses a difficult challenge because of the technical complexity of surgical resection and the fear of postoperative hepatic decompensation. We analyzed the outcome and prognostic factors in patients with large hepatocellular carcinoma (HCC ≥10 cm) after surgery. METHODS: We retrospectively investigated the medical records of 91 patients who had undergone hepatectomy between January 2006 and June 2010. A survival analysis was performed utilizing the Kaplan-Meier method and prognostic factors were evaluated using Cox regression analysis. RESULTS: Of the 91 patients evaluated, most tumors were associated with hepatitis B virus (HBV). The median tumor size was 12.3 cm (range, 10 to 21 cm), with microvascular invasion present in most patients. The postoperative mortality rate was 2.2%. The median disease-free survival and overall survival were six months and 41 months. The one-year, two-year, and three-year disease-free survival rates were 33.5%, 29.3%, and 18.8%, respectively. The one-year, two-year, and three-year overall survival rates were 73.9%, 63.7%, and 54.8%, respectively. Of the 89 surviving patients, 69 patients (77.5%) developed HCC recurrence during the mean follow-up period of 23.4 ± 15.9 months. On multivariate analysis, the statistically significant factors that predicted HCC recurrence were ALP ≥ 80 IU/mL (P = 0.009) and intrahepatic metastases (P = 0.013). CONCLUSIONS: Our study suggests that preoperative ALP levels (≥ 80 IU/L) and intrahepatic metastases could be utilized to monitor and predict recurrence in HCC patients

Clinical impact of diabetes mellitus on 2-year clinical outcomes following PCI with second-generation drug-eluting stents; Landmark analysis findings from patient registry: Pooled analysis of the Korean multicenter drug-eluting stent registry.

BackgroundPatients with diabetes mellitus are at an increased risk for adverse clinical events following percutaneous coronary interventions (PCI). However, the clinical impact of diabetes mellitus (DM) on second-generation drug-eluting stent (DES) implantation is not well-known. The aim of the current analysis was to examine the clinical impact of DM on clinical outcomes and the time sequence of associated risks in patients treated with second-generation DES.MethodsUsing patient-level data from two stent-specific, all-comer, prospective DES registries, we evaluated 1,913 patients who underwent PCI with second-generation DES between Feb 2009 and Dec 2013. The primary outcomes assessed were two-year major cardiac adverse events (MACE), composite endpoints of death from any cause, myocardial infarction (MI), and any repeat revascularization. We classified 0-1 year as the early period and 1-2 years as the late period. Landmark analyses were performed according to diabetes mellitus status.ResultsThere were 1,913 patients with 2,614 lesions included in the pooled dataset. The median duration of clinical follow-up in the overall population was 2.0 years (interquartile range 1.9-2.1). Patients with DM had more cardiovascular risk factors than patients without DM. In multivariate analyses, the presence of DM and renal failure were strong predictors of MACE and target-vessel revascularization (TVR). After inverse probability of treatment weighting (IPTW) analyses, patients with DM had significantly increased rates of 2-year MACE (HR 2.07, 95% CI; 1.50-2.86; P ConclusionsIn the second-generation DES era, the clinical impact of DM significantly increased the 2-year event rate of MACE, mainly caused by clinical events in the early period (0-1 year). Careful observation of patients with DM is advised in the early period following PCI with second-generation DES