Interpolated wave functions for nonadiabatic simulations with the fixed-node quantum Monte Carlo method

Simulating nonadiabatic effects with many-body wave function approaches is an open field with many challenges. Recent interest has been driven by new algorithmic developments and improved theoretical understanding of properties unique to electron-ion wave functions. Fixed-node diffusion Monte Caro is one technique that has shown promising results for simulating electron-ion systems. In particular, we focus on the CH molecule for which previous results suggested a relatively significant contribution to the energy from nonadiabatic effects. We propose a new wave function ansatz for diatomic systems which involves interpolating the determinant coefficients calculated from configuration interaction methods. We find this to be an improvement beyond previous wave function forms that have been considered. The calculated nonadiabatic contribution to the energy in the CH molecule is reduced compared to our previous results, but still remains the largest among the molecules under consideration.Comment: 7 pages, 3 figure

B Cell Activating Factor of the Tumor Necrosis Factor Family (BAFF) Behaves as an Acute Phase Reactant in Acute Pancreatitis

OBJECTIVE: To determine if B cell activating factor of the tumor necrosis factor family (BAFF) acts as an acute phase reactant and predicts severity of acute pancreatitis. METHODS: 40 patients with acute pancreatitis were included in this single center cohort pilot study. Whole blood and serum was analyzed on day of admission and nine consecutive days for BAFF, c-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT), and leucocyte numbers. Different severity Scores (Ranson, APACHE II, SAPS II, SAPS III) and the clinical course of the patient (treatment, duration of stay, duration ICU) were recorded. RESULTS: Serum BAFF correlates with CRP, an established marker of severity in acute pancreatitis at day of admission with a timecourse profil similar to IL-6 over the first nine days. Serum BAFF increases with Ranson score (Kruskal-Wallis: Chi2 = 10.8; p = 0.03) similar to CRP (Kruskal-Wallis: Chi2 = 9.4; p = 0.05 ). Serum BAFF, IL-6, and CRP levels are elevated in patients that need intensive care for more than seven days and in patients with complicated necrotizing pancreatitis. Discriminant analysis and receiver operator characteristics show that CRP (wilks-lambda = 0.549; ROC: AUC 0.948) and BAFF (wilks-lambda = 0.907; ROC: AUC 0.843) serum levels at day of admission best predict severe necrotizing pancreatitis or death, outperforming IL-6, PCT, and number of leucocytes. CONCLUSION: This study establishes for the first time BAFF as an acute phase reactant with predictive value for the course of acute pancreatitis. BAFF outperforms established markers in acute pancreatitis, like IL-6 and PCT underscoring the important role of BAFF in the acute inflammatory response