Initiation of Failure for Masonry Subject to In-Plane Loads through Micromechanics

A micromechanical procedure is used in order to evaluate the initiation of damage and failure of masonry with in-plane loads. Masonry material is viewed as a composite with periodic microstructure and, therefore, a unit cell with suitable boundary conditions is assumed as a representative volume element of the masonry. The finite element method is used to determine the average stress on the unit cell corresponding to a given average strain prescribed on the unit cell. Finally, critical curves representing the initiation of damage and failure in both clay brick masonry and adobe masonry are provided

Influence of perineural invasion in predicting overall survival and disease-free survival in patients With locally advanced gastric cancer

Background The aim of the present study was to evaluate the prognostic significance of perineural invasion (PNI) in locally advanced gastric cancer patients who underwent D2 gastrectomy and adjuvant chemotherapy. Methods The records of a series of 103 patients undergoing D2 gastrectomy with curative intent combined with adjuvant chemotherapy from January 2004 to December 2014 were retrospectively reviewed. Results PNI was positive in 47 (45.6%) specimens. The 1-, 3-, and 5-year overall survival rates were 81%, 55%, and 42%, respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 76%, 57%, and 49%, respectively. A multivariate analysis showed that age number of positive lymph nodes, T stage, and PNI were independently associated with overall survival. Regarding DFS, the multivariate analysis showed that only PNI was independently associated with DFS. Conclusions PNI and T stage and positive lymph nodes are independent markers of poor prognosis in patients with gastric cancer. PNI should be incorporated in the postoperative staging system for planning follow-up after surgery and in our opinion to propose more aggressive postoperative therapies in PNI-positive patients

Core charge distribution and self assembly of columnar phases: the case of triphenylenes and azatriphenylenes

<p>Abstract</p> <p>Background</p> <p>The relation betweeen the structure of discotic molecules and columnar properties, a crucial point for the realization of new advanced materials, is still largely unknown. A paradigmatic case is that hexa-alkyl-thio substituted triphenylenes present mesogenic behavior while the corresponding azatriphenylenes, similar in shape and chemical structure, but with a different core charge distribution, do not form any liquid crystalline mesophase. This study is aimed at investigating, with the help of computer simulations techniques, the effects on phase behaviour of changes of the charge distribution in the discotic core.</p> <p>Results</p> <p>We described the shape and the pair, dispersive and electrostatic, interactions of hexa alkyl triphenylenes by uniaxial Gay-Berne discs with embedded point charges. Gay-Berne parameters were deduced by fitting the dispersive energies obtained from an atomistic molecular dynamics simulation of a small sample of hexa-octyl-thio triphenylene molecules in columnar phase, while a genetic algorithm was used to get a minimal set of point charges that properly reproduces the ab anitio electrostatic potential. We performed Monte Carlo simulations of three molecular models: the pure Gay-Berne disc, used as a reference, the Gay-Berne disc with hexa-thio triphenylene point charges, the Gay-Berne disc with hexa-thio azatriphenylene point charges. The phase diagram of the pure model evidences a rich polymorphism, with isotropic, columnar and crystalline phases at low pressure, and the appearance of nematic phase at higher pressure.</p> <p>Conclusion</p> <p>We found that the intermolecular electrostatic potential among the cores is fundamental in sta-bilizing/destabilizing columnar phases; in particular the triphenylene charge distribution stabilizes the columnar structure, while the azatriphenylene distribution suppresses its formation in favor of the nematic phase. We believe the present model could be successfully employed as the basis for coarse-grained level simulations of a wider class of triphenylene derivatives.</p

Ambient and personal noise exposure assessment in a pasta factory

Noise pollution is one of the most important risk factors in industrial settings. This study is assessing ambient and personal noise exposure among workers of a pasta factory. Two kinds of measurements were taken; at a fixed work point in three areas and personal ones for different employees; for 8h at different times. Results for the measurements carried out at fixed sample points show that exposure times of ≤ 8h are the same. The highest noise levels are in the press and packaging areas. Worker's activity is well planned as their movements avoid staying for a long time in areas where their continuous noise exposure can exceed the most critical values. Dosimeter data can be a source of concern for the workers' health and therefore for their employers. Operators are engaged to work very close to machines; so they are subjected to levels of noise exposure different from that measured in fixed sample points. This study has further confirmed that the risk evaluation is not an exact science; as it doesn't consist only of technical and mechanical factors, but needs also to consider the factors connected to workers' interaction with the workplace

Economic analysis of bedside ultrasonography (US) implementation in an Internal Medicine department

The economic crisis, the growing healthcare demand, and Defensive Medicine wastefulness, strongly recommend the restructuring of the entire medical network. New health technology, such as bedside ultrasonography, might successfully integrate the clinical approach optimizing the use of limited resources, especially in a person-oriented vision of medicine. Bedside ultrasonography is a safe and reliable technique, with worldwide expanding employment in various clinical settings, being considered as "the stethoscope of the 21st century". However, at present, bedside ultrasonography lacks economic analysis. We performed a Cost-Benefit Analysis "ex ante", with a break-even point computing, of bedside ultrasonography implementation in an Internal Medicine department in the mid-term. Number and kind estimation of bedside ultrasonographic studies were obtained by a retrospective study, whose data results were applied to the next 3-year period (foresight study). All 1980 foreseen bedside examinations, with prevailing multiorgan ultrasonographic studies, were considered to calculate direct and indirect costs, while specific and generic revenues were considered only after the first semester. Physician professional training, equipment purchase and working time represented the main fixed and variable cost items. DRG increase/appropriateness, hospitalization stay shortening and reduction of traditional ultrasonography examination requests mainly impacted on calculated revenues. The break-even point, i.e. the volume of activity at which revenues exactly equal total incurred costs, was calculated to be 734 US examinations, corresponding to € 81,998 and the time considered necessary to reach it resulting 406 days. Our economic analysis clearly shows that bedside ultrasonography implementation in clinical daily management of an Internal Medicine department can produce consistent savings, or economic profit according to managerial choices (i.e., considering public or private targets), other than evident medical benefits

Anti-cyclic-citrullinated-protein-antibodies in psoriatic arthritis patients: how autoimmune dysregulation could affect clinical characteristics, retention rate of methotrexate monotherapy and first line biotechnological drug survival. A single center retrospective study

Aim: Occasional findings of anti-cyclic-citrullinated-protein-antibodies (anti-CCP) were rarely observed in psoriatic arthritis (PsA). The aim of our study is to evaluate whether the presence of anti-CCP can determine different clinical subsets and influence methotrexate monotherapy survival, and biotechnological drug retention rate. Methods: We conducted a retrospective study on PsA patients. All patients were required to fulfill the CASPAR criteria for PsA, and to present juxta-articular osteo-proliferative signs at X-ray. The exclusion criteria were age less than 18 years old, satisfaction of rheumatoid arthritis classification criteria, and seropositivity for rheumatoid factor. Clinical characteristics, anti-CCP titer, drug survival and comorbidities information were recorded for each patient. Statistical significance was set at p ⩽ 0.05. Results: Of 407 patients with PsA screened 113 were recruited. Twelve patients were anti-CCP positive. Methotrexate monotherapy survival was shorter in patients with anti-CCP (150 ± 48.3 weeks versus 535.3 ± 65.3 weeks; p = 0.026) [discontinuation risk hazard ratio (HR) = 2.389, 95% confidence interval (CI) 1.043, 5.473; p = 0.039] than those without. Significant shorter survival of first-line biotechnological drugs (b-DMARDs) was observed in the anti-CCP positive group than in that without (102.05 ± 24.4 weeks versus 271.6 ± 41.7 weeks; p = 0.005) with higher discontinuation risk (HR = 3.230, 95% CI 1.299, 8.028; p = 0.012). A significant higher rate of multi-failure (more than second-line b-DMARDs) was found in anti-CCP positive patients than in those without (50% versus 14%, p = 0.035). Conclusion: Anti-CCP in PsA could be suggestive of more severe disease, with worse drug survival of both methotrexate monotherapy and first-line b-DMARDs, and higher chance to be b-DMARDs multi-failure. So, they can be considered for more intensive clinical management of these patients

Stability of Dirac cone in artificial graphene

Trabajo presentado al 18th ETSF Workshop celebrado en Luxemburgo del 1 al 4 de Octubre de 2013.ETSF - European Theoretical Spectroscopy Facility I3 (211956).Peer Reviewe

A Score Index System for a Semi-Quantitative Assessment of Inhalation Risks at Contaminated Sites

Risk assessment of contaminated sites is typically applied following a tiered approach with increasing levels of complexity. In the standard risk-based corrective action (RBCA) procedure issued by the American Society for Testing and Materials (ASTM), the site-specific evaluation is carried out using fate and transport models that require a relatively large amount of input data. In this work, we introduce a site-specific score index system for a preliminary assessment of the inhalation risks related to contaminants in soil or groundwater that resembles the modeling approaches typically adopted for chemical risk assessment in the field of industrial hygiene. In the developed system, a risk index for the outdoor and indoor volatilization pathways is calculated as the ratio between the calculated concentration at the point of exposure for the contaminant of concern and the corresponding acceptable concentration in air. The concentration at the point of exposure for each contaminant of concern is estimated through simple algorithms that involve a limited number of indexes that depend on the parameters that affect the exposure scenario. This qualitative assessment is then converted into a semi-quantitative approach by introducing scaling factors that were calibrated using the ASTM RBCA fate and transport models. The procedure was validated against the standard RBCA procedure by performing a simple Monte Carlo analysis with 10,000 simulations with randomly varying site-specific parameters. The developed score index system resulted in a conservative estimate of the risks, with percentages of false negatives lower than 1% and false positives lower than 15%. This means that the developed system allows one to screen out sites from further evaluations in more than 80% of cases, while ensuring a conservative estimate of the expected risks. The application to a real case study of a contaminated site confirmed the suitability of the developed approach

Efficacy and safety of felbamate in children under 4 years of age: a retrospective chart review.

Background and purpose: To review our experience of the efficacy and tolerability of felbamate in children younger than 4 years. Methods: We used a retrospective chart review to identify 53 children with seizures who were younger than 4 years. Efficacy was evaluated based on the occurrence of responsiveness, defined as seizure frequency reduction of more than 50% for a minimum period of 4 months. Tolerability was based on parent-reported side effects. Results: Twenty-two (41%) patients resulted to be responders and 31 (59%) did not. By univariate analysis, those achieving seizure remission were probably much older, to have a shorter history of epilepsy and a lower frequency of seizures before felbamate therapy. The number of antiepileptic drugs (AEDs) used before felbamate therapy was the only significant predictor of the duration of response to felbamate, with a longer responsiveness to the drug seen in those who were placed under fewer than three AEDs before felbamate compared with those who had taken more than three (median, 16 months vs. 7 months; P < 0.0084). Side effects occurred in 30% of the subjects, but these did not require discontinuation of the drug. Discussion: Felbamate is an effective medication for a wide range of epilepsy syndromes in children younger than 4 years. Although caution is necessary when the drug is used in children, felbamate might represent a possible option for the treatment of epilepsy in this age group. Introduction The incidence of epilepsy is high during the first year of life and it declines steadily during childhood and adolescence. Few of the new antiepileptic drugs (AEDs) are indicated officially for children younger than 4 years [1–3]. None of them is approved for children younger than 2 years [1,3,4]. There is a striking discrepancy between the high incidence of epilepsy in infancy and the relatively few approved AEDs available for this age group [5]. Felbamate (2-phenyl-1,3-propanediol dicarbamate) is a derivative of the anti-anxiety drug meprobamate, exerting additional anticonvulsant and neuroprotective properties [6–8]. The drug has been approved since 1993 for the treatment of several types of epilepsy. Experimental studies suggested that felbamate might inhibit voltage-dependen

Comparative efficacy and safety of targeted therapies for BRAF-mutant unresectable or metastatic melanoma: Results from a systematic literature review and a network meta-analysis

Background: The objective of this study was to estimate the relative efficacy and safety of targeted therapies for the treatment of metastatic melanoma using a network meta-analysis (NMA). Methods: A systematic literature review (SLR) identified studies in Medline, Embase and Cochrane published until November 2020. Screening used prespecified eligibility criteria. Following a transitivity assessment across included studies, Bayesian NMA was conducted. Results: A total of 43 publications reporting 15 targeted therapy trials and 42 reporting 18 immunotherapy trials were retained from the SLR and considered for the NMA. Due to substantial between-study heterogeneity with immunotherapy trials, the analysis considered a network restricted to targeted therapies. Among combination therapies, encorafenib + binimetinib was superior to dabrafenib + trametinib for overall response rate (OR = 1.86; 95 % credible interval [CrI] 1.10, 3.17), superior to vemurafenib + cobimetinib with fewer serious adverse events (SAEs) (OR = 0.51; 95 % CrI 0.29, 0.91) and fewer discontinuations due to AEs (OR = 0.45; 95 % CrI 0.21, 0.96), and superior to atezolizumab + vemurafenib + cobimetinib with fewer SAEs (OR = 0.41; 95 % CrI 0.21, 0.82). Atezolizumab + vemurafenib + cobimetinib and encorafenib + binimetinib were generally comparable for efficacy endpoints. Among double combination therapies, encorafenib + binimetinib showed high probabilities of being better for all efficacy and safety endpoints. Conclusions: This NMA confirms that combination therapies are more efficacious than monotherapies. Encorafenib + binimetinib has a favourable efficacy profile compared to other double combination therapies and a favourable safety profile compared to both double and triple combination therapies