We prove analytic criteria for the existence of finite-time attracting and repelling material surfaces and lines in three-dimensional unsteady flows. The longest lived such structures define coherent ...structures in a Lagrangian sense. Our existence criteria involve the invariants of the velocity gradient tensor along fluid trajectories. An alternative approach to coherent structures is shown to lead to their characterization as local maximizers of the largest finite-time Lyapunov exponent field computed
directly from particle paths. Both approaches provide effective tools for extracting distinguished Lagrangian structures from three-dimensional velocity data. We illustrate the results on steady and unsteady ABC-type flows.
This multicenter, randomized trial compared capecitabine plus oxaliplatin (XELOX) with bolus fluorouracil (FU) and folinic acid (FA) as adjuvant therapy for patients with stage III colon cancer.
...Patients who had undergone curative resection were randomly assigned to XELOX (oxaliplatin 130 mg/m(2) on day 1 plus capecitabine 1,000 mg/m(2) twice daily on days 1 to 14 every 3 weeks for 24 weeks) or a standard bolus FU/FA adjuvant regimen (Mayo Clinic for 24 weeks or Roswell Park for 32 weeks). The primary study end point was disease-free survival (DFS).
The intention-to-treat population comprised 1,886 patients; 944 patients were randomly assigned to XELOX and 942 to FU/FA (Mayo Clinic, n = 664; Roswell Park, n = 278). After 57 months of follow-up for the primary analysis, 295 patients (31.3%) in the XELOX group had relapsed, developed a new primary colon cancer, or died compared with 353 patients (37.5%) in the FU/FA group (hazard ratio HR for DFS, 0.80; 95% CI, 0.69 to 0.93; P = .0045). The 3-year DFS rate was 70.9% with XELOX and 66.5% with FU/FA. The HR for overall survival (OS) for XELOX compared to FU/FA was 0.87 (95% CI, 0.72 to 1.05; P = .1486). The 5-year OS for XELOX and FU/FA were 77.6% and 74.2%, respectively. Follow-up is ongoing. Preplanned multivariate and subgroup analyses supported the robustness of these findings.
The addition of oxaliplatin to capecitabine improves DFS in patients with stage III colon cancer. XELOX is an additional adjuvant treatment option for these patients.
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•n-Pentane cracking studied over MFI in a wide range of acid site concentrations.•Tetrahedrally coordinated EFAl in proximity to BAS is responsible for higher rates.•Equal turnover ...frequency per BAS was found for samples free of EFAl.•Post-synthetic chemical modification enables tuning of catalytic activity.
The impact of the zeolite Brønsted and Lewis acid site concentration on the catalytic cracking of alkanes was explored using n-pentane and H-ZSM-5 as examples. Rates normalized to strong Brønsted acid sites (i.e., the turnover frequencies, TOF) showed that the two samples with the highest Al content had much higher TOF than all other samples. This difference has been unequivocally linked to the presence of extra-lattice alumina. Post-treatment of the zeolites with ammonium hexafluorosilicate and static calcination was used to vary the concentration of extra-lattice alumina. After extraction of extra-lattice alumina from the samples with high TOF, all TOFs were identical. IR spectra of adsorbed pyridine and NH3, coupled with 27Al MAS NMR, showed that the overall enhanced activity is associated with tetrahedrally coordinated extra-lattice alumina in close proximity to strong Brønsted acid sites. The TOF of these sites is approximately 40-times higher than the TOF on normal Brønsted acid sites.
Surgical resection of gastric cancer has produced suboptimal survival despite multiple randomized trials that used postoperative chemotherapy or more aggressive surgical procedures. We performed a ...randomized phase III trial of postoperative radiochemotherapy in those at moderate risk of locoregional failure (LRF) following surgery. We originally reported results with 4-year median follow-up. This update, with a more than 10-year median follow-up, presents data on failure patterns and second malignancies and explores selected subset analyses.
In all, 559 patients with primaries ≥ T3 and/or node-positive gastric cancer were randomly assigned to observation versus radiochemotherapy after R0 resection. Fluorouracil and leucovorin were administered before, during, and after radiotherapy. Radiotherapy was given to all LRF sites to a dose of 45 Gy.
Overall survival (OS) and relapse-free survival (RFS) data demonstrate continued strong benefit from postoperative radiochemotherapy. The hazard ratio (HR) for OS is 1.32 (95% CI, 1.10 to 1.60; P = .0046). The HR for RFS is 1.51 (95% CI, 1.25 to 1.83; P < .001). Adjuvant radiochemotherapy produced substantial reduction in both overall relapse and locoregional relapse. Second malignancies were observed in 21 patients with radiotherapy versus eight with observation (P = .21). Subset analyses show robust treatment benefit in most subsets, with the exception of patients with diffuse histology who exhibited minimal nonsignificant treatment effect.
Intergroup 0116 (INT-0116) demonstrates strong persistent benefit from adjuvant radiochemotherapy. Toxicities, including second malignancies, appear acceptable, given the magnitude of RFS and OS improvement. LRF reduction may account for the majority of overall relapse reduction. Adjuvant radiochemotherapy remains a rational standard therapy for curatively resected gastric cancer with primaries T3 or greater and/or positive nodes.
We show how spectral submanifold (SSM) theory can be used to provide analytic predictions for the response of periodically forced multi-degree-of-freedom mechanical systems. These predictions include ...an explicit criterion for the existence of isolated forced responses that will generally be missed by numerical continuation techniques. Our analytic predictions can be refined to arbitrary precision via an algorithm that does not require the numerical solutions of the mechanical system. We illustrate all these results on low- and high-dimensional nonlinear vibration problems. We find that our SSM-based forced response predictions remain accurate in high-dimensional systems, in which numerical continuation of the periodic response is becoming computationally expensive.
The emergence of coherent Lagrangian swirls (CLSs) among submesoscale motions in the ocean is illustrated. This is done by applying recent nonlinear dynamics tools for Lagrangian coherence detection ...on a surface flow realization produced by a data-assimilative submesoscale-permitting ocean general circulation model simulation of the Gulf of Mexico. Both mesoscale and submesoscale CLSs are extracted. These extractions prove the relevance of coherent Lagrangian eddies detected in satellite-altimetry–based geostrophic flow data for the arguably more realistic ageostrophic multiscale flow.
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