An algebraic proof of Bogomolov-Tian-Todorov theorem

We give a completely algebraic proof of the Bogomolov-Tian-Todorov theorem. More precisely, we shall prove that if X is a smooth projective variety with trivial canonical bundle defined over an algebraically closed field of characteristic 0, then the L-infinity algebra governing infinitesimal deformations of X is quasi-isomorphic to an abelian differential graded Lie algebra.Comment: 20 pages, amspro

The Impact of Hospital Costing Methods on Cost-Effectiveness Analysis: A Case Study

Background: Several methods exist to cost hospital contacts when estimating the cost effectiveness of a new intervention. However, the implications of choosing a particular approach remain unclear. We compare the use of the three main diagnosis-related group (DRG)-based national unit costs in England to determine whether choice of approach can impact on economic evaluation results. Methods: A cost-utility model was developed to compare secondary fracture prevention models of care for hip fracture patients, using data from large primary and hospital care administrative datasets in England. A healthcare and personal social services payer perspective was adopted, and utilities were informed by a meta-regression. Hospital resource use was valued using three DRG-based unit costs, and regression-based costing models were developed using data from 13,906 patients to inform the model health states. Results: Finished consultant episode (FCE)-level reference costs resulted in the highest costs on admission (£9075) and in the year of the fracture (£14,440). Relative to FCE-level costs, spell-level tariffs led to the lowest total hospital care costs per patient within 1 year of fracture (− £3691) compared with spell-level reference costs (− £2106). At a £20,000/quality-adjusted life-year threshold, using spell-level reference costs or spell-level tariffs, the introduction of a nurse-led fracture liaison service model of care was the cost-effective alternative. However, using FCE-level reference costs, usual care was the cost-effective option. Conclusions: Our results show that, conditional on the set of national unit costs adopted, the costs of hip fracture may vary considerably and different decisions may be reached regarding the introduction of new healthcare interventions

HIV-Reverse Transcriptase Inhibition: Inclusion of Ligand-Induced Fit by Cross-Docking Studies

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) have, in addition to the nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitors (PIs), a definitive role in the treatment of HIV-1 infections. Since the appearance of HEPT and TIBO, more than 30 structurally different classes of compounds have been reported as NNRTIs, which are specific inhibitors of HIV-1 replication, targeting the HIV-1 reverse transcriptase (RT). Nevirapine and delavirdine are the first formally licensed for clinical use, and others have been licensed afterward, while several are in preclinical or clinical development. The NNRTIs interact with a specific site of HIV-1 RT (nonnucleoside binding site, NNBS) that is close to, but distinct from, the NRTI binding site. In this work we report the application of the Autodock program assessing its usability through reproduction of 41 NNRTI experimental bound conformations. Moreover, cross-docking experiments on the wild-type and mutated RT forms were conducted to take into account the enzyme flexibility as a valuable tool for structure-based drug design (SBDD) studies and to gain insight on the mode of action of new anti-HIV agents active against both wild-type and resistant strains