Most mental processes consist of a number of processing steps that are executed sequentially. The timing of the individual mental operations can usually only be estimated indirectly, from the pattern ...of reaction times. In vision, however, many processing steps are associated with the modulation of neuronal activity in early visual areas. Here we exploited this association to elucidate the time course of neuronal activity related to each of the self-paced mental processing steps in complex visual tasks. We trained monkeys to perform two tasks, search-trace and trace-search, which required performing a sequence of two operations: a visual search for a specific color and the mental tracing of a curve. We used multielectrode recording techniques to monitor the representations of multiple visual items in area V1 at the same time and found that the relevant curve as well as the target of visual search evoked enhanced neuronal activity with a timing that depended on the order of operations. This modulation of neuronal activity in early visual areas could allow these areas to (1) act as a cognitive blackboard that permits the exchange of information between successive processing steps of a sequential visual task and to (2) contribute to the orderly progression of task-dependent endogenous attention shifts that are driven by task structure and evolve over hundreds of milliseconds.
Purpose:
Several authors have recommended a 2 mm tolerance for multileaf collimator (MLC) positioning in sliding window treatments. In volumetric modulated arc therapy (VMAT) treatments, however, the ...optimal tolerance for MLC positioning remains unknown. In this paper, the authors present the results of a multicenter study to determine the optimal tolerance for both techniques.
Methods:
The procedure used is based on dynalog file analysis. The study was carried out using seven Varian linear accelerators from five different centers. Dynalogs were collected from over 100 000 clinical treatments and in‐house software was used to compute the number of tolerance faults as a function of the user‐defined tolerance. Thus, the optimal value for this tolerance, defined as the lowest achievable value, was investigated.
Results:
Dynalog files accurately predict the number of tolerance faults as a function of the tolerance value, especially for low fault incidences. All MLCs behaved similarly and the Millennium120 and the HD120 models yielded comparable results. In sliding window techniques, the number of beams with an incidence of hold‐offs >1% rapidly decreases for a tolerance of 1.5 mm. In VMAT techniques, the number of tolerance faults sharply drops for tolerances around 2 mm. For a tolerance of 2.5 mm, less than 0.1% of the VMAT arcs presented tolerance faults.
Conclusions:
Dynalog analysis provides a feasible method for investigating the optimal tolerance for MLC positioning in dynamic fields. In sliding window treatments, the tolerance of 2 mm was found to be adequate, although it can be reduced to 1.5 mm. In VMAT treatments, the typically used 5 mm tolerance is excessively high. Instead, a tolerance of 2.5 mm is recommended.
Terrestrial environmental and biological systems are being threatened by the tremendous amount of human carbon dioxide emissions. Therefore, it is crucial to develop a sustainable energy system based ...on CO
2
as chemical feedstock. In this review, an introduction to the CO
2
activation and transformation has been made, together with a more comprehensive study of the catalytical reduction of CO
2
to methane, methanol, and formic acid, which are currently contemplated as chemical feedstocks and/or promising energy carriers and alternative fuels.
Pru p 1 (a Bet v 1 homologue) and Pru p 3 (a nonspecific lipid transfer protein; nsLTP) are major allergenic proteins in peach fruit, but differ in their abundance and stability. Pru p 1 has low ...abundance and is highly labile and was purified after expression as a recombinant protein in Escherichia coli. Pru p 3 is highly abundant in peach peel and was purified by conventional methods. The identities of the proteins were confirmed by sequence analysis and their masses determined by MS analysis. The purified proteins reacted with antisera against related allergens from other species: Pru p 1 with antiserum to Bet v 1 and Pru p 3 with antiserum to Mal d 3 (from apple). The presence of secondary and tertiary structure was demonstrated by circular dichroism (CD) and high field NMR spectroscopy. CD spectroscopy also showed that the two proteins differed in their stability at pH 3 and in their ability to refold after heating to 95°C. Thus, Pru p 1 was unfolded at pH 3 even at 25°C but was able to refold after heating to 95°C at pH 7.5. In contrast, Pru p 3 was unable to refold after heating under neutral conditions but readily refolded after heating at pH 3.
Consumption of fresh apples can cause allergy in susceptible individuals. A competitive enzyme-linked immunosorbent assay (ELISA) has been developed to determine Mal d 1 levels in apple pulp using a ...monoclonal antibody (BIP-1). The ELISA was able to rank ten cultivars according to their Mal d 1 content (between 3.8 and 72.5 μg/g pulp). For the first time, it has been demonstrated that growing conditions and postharvest storage, using three different treatments over a 5 month period in 2 consecutive years, increase Mal d 1 expression at a translational and transcriptional level (3.5- and 8.5-fold under controlled atmosphere storage). Expression of three major Mal d 1 isoforms was observed by real-time polymerase chain reaction over the 5 month storage period, and Mal d 1.02 was the most highly expressed isoform. In conclusion, Mal d 1 gene expression was significantly increased during modified atmosphere storage. Individuals suffering from birch pollen−apple allergy syndrome might experience fewer problems consuming freshly picked apples. Keywords: Apple; allergens; Bet v 1; cultivar; Mal d 1; Mal d 1 expression; PR 10; storage
The inclusion complexes formed by chalcone and 2′,4′-dihydroxychalcone with β-cyclodextrin have been studied combining experimental (phase solubility diagrams, Fourier transform infrared ...spectroscopy) and molecular modeling (molecular dynamics, quantum mechanics/molecular mechanics calculations) techniques. The formation constants of the complexes were determined at different temperatures, and the thermodynamic parameters of the process were obtained. The inclusion of chalcone in β-cyclodextrin is an exothermic process, while the inclusion of 2′,4′-dihydroxychalcone is endothermic. Free energy profiles, derived from umbrella sampling using molecular dynamics simulations, were constructed to analyze the binding affinity and the complexation reaction at a molecular level. Hybrid QM/MM calculations were also employed to obtain a better description of the energetic and structural aspects of the complexes. The intermolecular interactions that stabilize both inclusion complexes were characterized by means of quantum atoms in molecules theory and reduce density gradient method. The calculated interactions were experimentally observed using FTIR.
Consumption of apples can provoke severe allergic reactions, in susceptible individuals, due to the presence of the allergen Mal d 3, a nonspecific lipid transfer protein, found largely in the fruit ...skin. Levels of Mal d 3 were determined in peel as a function of apple cultivar, position of the fruit growing on the tree, apple maturity, and postharvest storage by ELISA. As the apples mature, Mal d 3 levels increased, although the rate was dependent on cultivar and tree position. During storage, levels of Mal d 3 decreased in all cultivars (cvs. Cox, Jonagored, and Gala), the rate of overall decrease being greatest under controlled atmosphere conditions. There was no correlation between Mal d 3 levels and total apple peel protein, indicating specific alterations in Mal d 3 expression. Thus pre- and postharvest treatments (i.e., storage) can modify the allergen load in apple peel, the highest levels being found in overly mature and freshly harvested fruits. Keywords: Apple; allergens; nonspecific lipid transfer protein; Mal d 3; cultivar; storage; maturity; nsLTP; Mal d 3 expression
Background and importance Clostridium difficile (CD) colonises the human intestinal tract after the normal flora has been disrupted (in association with antibiotic therapy). Clinical guidelines use ...fidaxomicin as first-line treatment in patients at greater risk for recurrence (age >65 years, compromised immunity, severe CD infection) in accordance with 2021 Infectious Diseases Society of America (IDSA).Aim and objectivesEvaluation of the cost increase in the treatment of CD if patients are treated with fidaxomicin instead of vancomycin after the failure of first-line treatment or as first-line treatment according to the age recommendations of the IDSA.Material and methodsRetrospective observational study that included patients diagnosed with pseudomembranous colitis and treated with oral vancomycin for CD from 1 October 2020 to 30 September 2021. Clinical sources used were from FarmaTools and the Electronic Medical Record Selene.Results97 patients were analysed; 48.45% men, median age 72 (SD 16) years. 9 were empirically treated. 88 pacients were positive for CD. 5 patients died from another pathology during treatment (3 during the first-line and 2 during the second-line treatment).73 patients (75.26%) (43.84% men) only needed one line of treatment with vancomycin to achieve a cure. The cost of vancomycin treatment for these patients was €3216.19 patients (19.59%) (63.16% men) required a second (15 patients) or third line (4 patients) of treatment after the failure of the previous lines. The cost of vancomycin treatment for these patients was €2266. These patients could have been treated with fidaxomicin. The total cost would have been increased to €30 300.71 patients (73%) at the time of diagnosis were older than 65 years; 83% first line, 9.86% second line and 7.14% third line. The cost of vancomycin treatment for these patients was €5461. Following the IDSA criteria, these patients could have been treated from the beginning with fidaxomicin. The total cost would have been increased to €102 453.Conclusion and relevanceThe use of fidaxomicin represents a very high increase in healthcare costs compared to vancomycin. In our study all the patients were cured with the use of vancomycin. It should also be noted that in clinical trials and meta-analyses, fidaxomicin achieves a modest superior efficacy compared to vancomycin.References and/or acknowledgementsConflict of interestNo conflict of interest
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