By stacking various two-dimensional (2D) atomic crystals on top of each other, it is possible to create multilayer heterostructures and devices with designed electronic properties. However, various ...adsorbates become trapped between layers during their assembly, and this not only affects the resulting quality but also prevents the formation of a true artificial layered crystal upheld by van der Waals interaction, creating instead a laminate glued together by contamination. Transmission electron microscopy (TEM) has shown that graphene and boron nitride monolayers, the two best characterized 2D crystals, are densely covered with hydrocarbons (even after thermal annealing in high vacuum) and exhibit only small clean patches suitable for atomic resolution imaging. This observation seems detrimental for any realistic prospect of creating van der Waals materials and heterostructures with atomically sharp interfaces. Here we employ cross sectional TEM to take a side view of several graphene-boron nitride heterostructures. We find that the trapped hydrocarbons segregate into isolated pockets, leaving the interfaces atomically clean. Moreover, we observe a clear correlation between interface roughness and the electronic quality of encapsulated graphene. This work proves the concept of heterostructures assembled with atomic layer precision and provides their first TEM images.
•Quality parameters were maintained after the application of chitosan coatings.•Procyanidin by-products enhanced the antioxidant activity of fresh blueberries.•Chitosan coating of blueberries delayed ...the yeast and mold growth during storage.
The aim of this work was to evaluate the efficacy of an innovative edible coating, based on chitosan from mushrooms enriched with procyanidins extracted from grape seeds, on fresh blueberry quality maintenance, (weight loss, pH, dry matter, colour, firmness and antioxidant activity) and microbial growth, during 14 days of storage at 4 °C.
For weight loss, pH and dry matter no relevant differences were detected among the control and the differently coated samples at each considered storage time. Chitosan and chitosan + procyanidins coatings promoted a slight decrease of luminosity and an increase of blue hue colour of blueberry samples during the whole storage period. The use of coating promoted an increase in the antiradical activity that was the highest in blueberries coated with chitosan + procyanidins. Microbiological analysis results indicated that the chitosan-based coated samples had a significantly higher yeast and mould growth inhibition compared to the uncoated sample.
Edible films or coatings could be used as an alternative way of conservation, because of their ability to reduce respiration and transpiration rate, maintain firmness and generally delay fruit ...senescence. The aim of this research was to evaluate the influence of different types of coating: sodium alginate (Al), pectin (Pe) and sodium alginate plus pectin (Al + Pe), on some blueberries quality characteristics, cell viability and microbial growth during 14 days of storage at 4 °C.
Blueberry samples differently coated did not show significant differences in weight loss, pH, soluble solid and dry matter content. However, the application of Al, Pe and Al + Pe improved the firmness of blueberry samples as compared to the uncoated one. Changes in the surface reflection properties in the coated blueberries induced a general lower lightness and a more intense blue hue colour than the control sample. The microbiological results indicated that the coating of blueberry, in particular with Al or Pe, significantly reduced the growth kinetics of yeasts and mesophilic aerobic bacteria.
•Coating induced a decrease of lightness and an increase of blue colour in berries.•Firmness of blueberries was improved by application of coating.•Alginate/pectin coating reduced the growth of yeasts and mesophilic aerobic bacteria.
The dilemma that neurotheorists face is that (1) detailed biophysical models that can be constrained by direct measurements, while being of great importance, offer no immediate insights into ...cognitive processes in the brain, and (2) high-level abstract cognitive models, on the other hand, while relevant for understanding behavior, are largely detached from neuronal processes and typically have many free, experimentally unconstrained parameters that have to be tuned to a particular data set and, hence, cannot be readily generalized to other experimental paradigms. In this contribution, we propose a set of “first principles” for neurally inspired cognitive modeling of memory retrieval that has no biologically unconstrained parameters and can be analyzed mathematically both at neuronal and cognitive levels. We apply this framework to the classical cognitive paradigm of free recall. We show that the resulting model accounts well for puzzling behavioral data on human participants and makes predictions that could potentially be tested with neurophysiological recording techniques.
Katkov et al. propose a set of “first principles,” neurally inspired cognitive dynamics of memory recall as transitions driven by overlaps between long-term neuronal representations. These dynamics can be analyzed mathematically and account for some of the classical observations in free recall literature.
Presently, most business-to-consumer interaction uses consumer profiling to elaborate and deliver personalized products and services. It has been observed that these practices can be ...welfare-enhancing if properly regulated. At the same time, risks related to their abuses are present and significant, and it is no surprise that in recent times, personalization has found itself at the centre of the scholarly and regulatory debate. Within currently existing and forthcoming regulations, a common perspective can be found: given the capacity of microtargeting to potentially undermine consumers’ autonomy, the success of the regulatory intervention depends primarily on people being aware of the personality dimension being targeted. Yet, existing disclosures are based on an individualized format, focusing solely on the relationship between the professional operator and its counterparty; this approach operates in contrast to sociological studies that consider interaction and observation of peers to be essential components of decision making. A consideration of this “relational dimension” of decision making is missing both in consumer protection and in the debate on personalization. This article defends that consumers’ awareness and understanding of personalization and its consequences could be improved significantly if information was to be offered according to a relational format; accordingly, it reports the results of a study conducted in the streaming service market, showing that when information is presented in a relational format, people’s knowledge and awareness about profiling and microtargeting are significantly increased. The article further claims the potential of relational disclosure as a general paradigm for advancing consumer protection.
Modifications to common radiographic techniques have resulted from the challenges presented by the COVID-19 pandemic. Reports exist regarding the potential benefits of undertaking mobile radiography ...through side room windows. The aim of this study was to evaluate the impact on image quality and exposure factors when undertaking such examinations.
A phantom based study was undertaken using a digital X-ray room. Control acquisitions, using a commercially available image quality test tool, were performed using standard mobile chest radiography acquisition factors. Image quality (physical and visual), incidence surface air kerma (ISAK), Exposure Index (EI) and Deviation Index (DI) were recorded. Image quality and radiation dose were further assessed for two additional (experimental) scenarios, where a side room window was located immediately adjacent to the exit port of the light beam diaphragm. The goal of experimental scenario one was to modify exposure factors to maintain the control ISAK. The goal of experimental scenario two was to modify exposure factors to maintain the control EI and DI. Dose and image quality data were compared between the three scenarios.
To maintain the pre-window (control) ISAK (76 μGy), tube output needed a three-fold increase (90 kV/4 mAs versus 90 kV/11.25 mAs). To maintain EI/DI a more modest increase in tube output was required (90 kV/8 mAs/ISAK 54 μGy). Physical and visual assessments of spatial resolution and signal-to-noise ratio were indifferent between the three scenarios. There was a slight statistically significant reduction in contrast-to-noise ratio when imaging through the glass window (2.3 versus 1.4 and 1.2; P = 0.005).
Undertaking mobile X-ray examinations through side room windows is potentially feasible but does require an increase in tube output and is likely to be limited by minor reductions in image quality.
Mobile examinations performed through side room windows should only be used in limited circumstances and future clinical evaluation of this technique is warranted.
The aim of this work was to quantify the recovery of juice and bioactive compounds of apple and carrot mashes treated by the electrotechnologies (PEF or OH) at different pre-heating temperatures (40, ...60 or 80 °C), considering thermal and electric field based cell disintegration.
In general, a higher cell disintegration resulting from the applied pre-treatments also resulted in higher juice yield (around 10% increase for carrot and 5% for apple compared to untreated). Regarding the carotenoid content of obtained carrot juices, only the PEF pre-treatment at 20 °C resulted in an increased extractability. A release of total polyphenols from apples into the juice increased in all pre-treated samples compared to the control. This study suggests that a combined pre-treatment can further improve the cell disintegration and juice yield and may have the potential to increase the recovery of bioactive compounds depending on the treatment parameters.
Thermal treatment followed by PEF or conducted by OH can still improve the cell disintegration and yield of juice.
Moreover, the combination of thermal and electric field effects may also improve the recovery of bioactive compounds depending on the chosen treatment conditions. Therefore, the combined treatments show high potentiality for the application at industrial level to improve the release of the juice and at the same time to obtain novel products with high quality.
•Thermal treatment followed by PEF or OH improved cell disintegration and juice yield.•Polyphenol content increased due to the thermal effects.•Stronger electropermeabilization effect for juice yield of PEF than OH treated samples.
Wheat flour replacement by rice flour is a key strategy in gluten-free batter production. Rice flour needs hydrocolloids to offset the development of the network of the mix. In this context, the aim ...of this work was to analyze the influence of chitosan (0–1 g/100 g of batter) addition on the microstructural, rheological and thermal properties of wheat:rice flours batters (100:0; 70:30, 30:70 and 0:100 (g/g)). Results showed that increasing replacement of wheat flour by rice one decreased the consistency (K) and the yield stress (τ0), and increased the flow behavior index (n) because of the absence or lower gluten content. However, the addition of only 0.25 g/100 g chitosan to rice flour formulation (0:100 (g/g)) increased its viscosity (from 371 to 1006 mPa s), exhibiting a rheological behavior similar to wheat flour formulation (100:0 (g/g) (1050 mPa s)). Chitosan enhanced consistency and structural agglomeration, and the interaction among ingredients, especially in batters with high content of rice flour (30:70 and 0:100 (g/g)). Lastly, chitosan incorporation did not significantly modify thermal properties, excepting in rice-flour batters (0:100 (g/g)), reducing Tm, ΔHm, and thus, increasing the bound water content (from 17 to 32 g/100 g).
•Chitosan (CH) increases viscosity in rice flour-based batters.•CH addition to rice flour based-batters improves structural agglomeration.•CH addition to wheat-rice flours batters do not influence their thermal behavior.
The aim of this study was to analyze the efficacy of an early start of NIV in ALS patients, evaluating respiratory and ventilatory parameters.
Functional respiratory parameters and arterial blood gas ...analysis were evaluated in forty-six patients. All patients were informed about the benefits and possible adverse effects of therapeutic support with NIV and divided in two groups based on the compliance to early start therapy with NIV (Group A) or not (Group B).
Among 46 ALS patients consecutively visited in our Unit, we included 20 patients in the Group A and 16 in the Group B. We have emphasized the importance of the early use of NIV stressing the difference between two groups analyzed, particularly in terms of pulmonary function tests and arterial blood gas analysis. Significant correlation was observed between Vital Capacity (VC), Forced Expiratory volume in one second (FEV1), and maximal inspiratory pressures (PImax).
Our study highlights the importance of noninvasive mechanical ventilation as a treatment for ALS patients and also shows the early start of NIV as an important approach in order to postpone the functional decline and the decrease of respiratory muscle strength.
Chronic obstructive pulmonary disease (COPD) has been associated with a high frequency of arrhythmias. Atrial fibrillation (AF) is one of the most common arrhythmias and causes substantial morbidity ...and mortality. Emerging risk factors for the development of AF include a variety of breathing disorders like COPD. Few studies have analyzed the role of reduced lung function and respiratory acidosis in predicting AF. Aim of the current study was to investigate the role of hypercapnia, pulmonary systolic hypertension and lung function impairment in COPD patients, as risk factors for atrial fibrillation development.
We evaluated a population of individuals consecutively hospitalized for COPD exacerbation and hypercapnic respiratory failure between January 2012 and January 2013; among them we selected a subgroup of patients presenting a paroxysmal episode of atrial fibrillation. All patients underwent pulmonary function tests, haemogasanalysis, electrocardiogram and transthoracic echocardiography.
Among the 193 subjects evaluated, 35 individuals with AF and COPD were enrolled in the study. Risk of new AF was higher in those subjects with lower FEV1 and higher PaCO2 values, also there was a significantly increased prevalence of AF in patients with higher value of Pulmonary Artery Systolic Pressure (PASP), obtained by transthoracic echocardiography. Linear correlation between variables revealed a direct relationships between hypercapnia and PASP and left and right atrial areas.
Impaired pulmonary function, hypercapnia and high values of PASP are independent predictors of incident AF.
PDF
