2,982 research outputs found

    Feature-based tuning of simulated annealing applied to the curriculum-based course timetabling problem

    Full text link
    We consider the university course timetabling problem, which is one of the most studied problems in educational timetabling. In particular, we focus our attention on the formulation known as the curriculum-based course timetabling problem, which has been tackled by many researchers and for which there are many available benchmarks. The contribution of this paper is twofold. First, we propose an effective and robust single-stage simulated annealing method for solving the problem. Secondly, we design and apply an extensive and statistically-principled methodology for the parameter tuning procedure. The outcome of this analysis is a methodology for modeling the relationship between search method parameters and instance features that allows us to set the parameters for unseen instances on the basis of a simple inspection of the instance itself. Using this methodology, our algorithm, despite its apparent simplicity, has been able to achieve high quality results on a set of popular benchmarks. A final contribution of the paper is a novel set of real-world instances, which could be used as a benchmark for future comparison

    Fully Polarizable QM/Fluctuating Charge Approach to Two-Photon Absorption of Aqueous Solutions

    Get PDF
    We present the extension of the quantum/classical polarizable fluctuating charge model to the calculation of single residues of quadratic response functions, as required for the computational modeling of two-photon absorption cross-sections. By virtue of a variational formulation of the quantum/classical polarizable coupling, we are able to exploit an atomic orbital-based quasienergy formalism to derive the additional coupling terms in the response equations. Our formalism can be extended to the calculation of arbitrary order response functions and their residues. The approach has been applied to the challenging problem of one- and two-photon spectra of rhodamine 6G (R6G) in aqueous solution. Solvent effects on one- and two-photon spectra of R6G in aqueous solution have been analyzed by considering three different approaches, from a continuum (QM/PCM) to two QM/MM models (non-polarizable QM/TIP3P and polarizable QM/FQ). Both QM/TIP3P and QM/FQ simulated OPA and TPA spectra show that the inclusion of discrete water solvent molecules is essential to increase the agreement between theory and experiment. QM/FQ has been shown to give the best agreement with experiments

    Benign hepatocellular nodules of healthy liver: focal nodular hyperplasia and hepatocellular adenoma

    Get PDF
    Owing to the progress of imaging techniques, benign hepatocellular nodules are increasingly discovered in the clinical practice. This group of lesions mostly arises in the context of a putatively normal healthy liver and includes either pseudotumoral and tumoral nodules. Focal nodular hyperplasia and hepatocellular adenoma are prototypical examples of these two categories of nodules. In this review we aim to report the main pathological criteria of differential diagnosis between focal nodular hyperplasia and hepatocellular adenoma, which mainly rests upon morphological and phenotypical features. We also emphasize that for a correct diagnosis the clinical context such as sex, age, assumption of oral contraceptives, associated metabolic or vascular disturbances is of paramount importance. While focal nodular hyperplasia is a single entity epidemiologically more frequent than adenoma, the latter is representative of a more heterogeneous group which has been recently and extensively characterized from a clinical, morphological, phenotypical and molecular profile. The use of the liver biopsy in addition to imaging and the clinical context are important diagnostic tools of these lesions. In this review we will survey their systematic pathobiology and propose a diagnostic algorithm helpful to increase the diagnostic accuracy of not dedicated liver pathologists. The differential diagnosis between so-called typical and atypical adenoma and well differentiated hepatocellular carcinoma will also be discussed

    Data of safety in a single-center alemtuzumab treated population

    Get PDF
    Alemtuzumab is approved for highly active MS and, in Europe, can be employed after other disease-modifying treatments (DMTs) as an escalation approach or first therapeutic option. The occurrence of secondary autoimmune adverse events and infections differs depending on the employed approach. In the manuscript entitled “Alemtuzumab treatment of multiple sclerosis in real-world clinical practice: report from a single Italian center” by di Ioia M. and collaborators, efficacy and safety data of alemtuzumab were evaluated in a real-world MS population. The aim of the article is to describe in detail the unexpected serious adverse events which occurred in this cohort during and after the administration of the alemtuzumab treatment. Adverse events were observed in 45,7% of the patients. These events were ranked as severe in 23% of the patients. We reported, in particular, cases of autoimmune hemolytic anemia (AIHA), pancytopenia, viral hepatitis E and noninfectious meningo-encephalomyelitis

    A real-time RT-PCR assay for molecular identification and quantitation of feline morbillivirus RNA from biological specimens.

    Get PDF
    The aim of this study was to develop a real-time RT-PCR to detect and quantitate feline morbillivirus (FeMV) RNA in biological samples. Primers and probe were targeted on a conserved region of FeMV P/V/C gene. To validate the assay with field samples, a total number of specimens of cats have been recruited including 264 urine and blood samples and compared with a generic RT-PCR targeting the L protein encoding gene of morbilliviruses. In addition, 385 tissue samples from 35 carcasses of cats have been also employed. RNA titres were low in all tested samples. Results also indicated the absence of cross-reaction with related morbilliviruses and existing pathogens of cats. However, in tissues with low levels of FeMV RNA, the presence of viral antigen was confirmed by immunohistochemistry targeting the N viral protein. This newly described assay allows for a rapid, accurate and reliable quantitative detection of FeMV RNA that can be applied for diagnostics and research studies

    Delayed gastric emptying after pancreatoduodenectomy: One complication, two different entities

    Get PDF
    Background: Delayed gastric emptying (DGE) is a common complication after pancreatoduodenectomy associated with a low complication burden but a prolonged hospital stay. The present study aimed to characterize DGE, with a particular focus on its subtypes and related predictors.Methods: A 2-center retrospective analysis was performed including consecutive pancreatoduodenectomy over 5 years. Primary delayed gastric emptying (pDGE) and secondary delayed gastric emptying (sDGE) were defined according to the presence of concomitant causing factors. Predictors of DGE, pDGE and sDGE were assessed through logistic regression.Results: Out of 1,170 patients considered, 188 developed delayed gastric emptying (16.1%). Most DGE (71.8%) were secondary. sDGE resolved later (P 1/4 .007), with hospital stay, duration of total parenteral nutrition, and of enteral nutrition being longer than for pDGE (all P < .005). Smoking status, total operative time, indication for surgery other than pancreatic cancer, estimated blood loss, and soft pancreatic texture were independent predictors of DGE. In the subgroup analysis of pDGE, smoking was the only independent predictor, whereas pylorus-preservation was a protective factor. Smoking, indication for surgery, estimated blood loss, soft gland texture, and main pancreatic duct diameter were independent predictors of sDGE.Conclusion: DGE after pancreatoduodenectomy consists of 2 different subtypes. The primary form re-solves earlier, and its occurrence might be reduced by pylorus preservation. For the secondary form, clinicians should focus on preventing and treating other trigger complications. The diagnosis of the DGE subtype has critical therapeutic implications and paves the way for further systematic studies.(c) 2022 Elsevier Inc. All rights reserved
    corecore